Tag Archives: traffic calming

Economic Merits of Road Diets and Traffic Calming

By Dom Nozzi, AICP

In a great many cases, “improved safety” is a reason cited as a rationale for adding travel lanes to a road (“widening” a road). Indeed, because “improved safety” is a “moral high ground” argument (i.e., the argument should be accepted for ethical reasons), the safety rationale is perhaps the most common reason given for why a road “must” be widened.

In effect, public policy makers, when confronted with the “public safety” justification, are forced into an uncomfortable position when a decision must be made to widen or not widen a road: Either agree to the widening, or take a position that seems to suggest an uncaring attitude toward public safety.

It comes as no surprise that a large number of decision-makers are persuaded solely on the basis of the public safety argument.

Because road widenings are enormously expensive, speed up car traffic, and can profoundly worsen quality of life as well as accelerate strip commercial development and urban sprawl, we must be certain that road widenings do, in fact, deliver on the promise of dramatically improved safety.

The Forgiving Road

The “Forgiving Road” is a road that “forgives” a motorist when a driving mistake is made. That is, being reckless, or driving at high-speeds, or driving inattentively is not followed by the “punishment” of consequences such as crashing into something on the side of the road. For several decades, we have designed forgiving roads. We have been pulling buildings, parked cars, pedestrians, bicyclists, trees and other “obstructions” away from the sides of roads so that even an unskilled motorist can travel at high speeds without crashing into something.

The forgiving road was thought to be a way to promote “safety”(the hidden agenda, for many, was to promote high-speed travel by large volumes of car traffic).

Of course-human nature being what it is-such a design encourages reckless, high-speed, inattentive driving because human psychology compels us to tend to drive at the highest speed that still feels safe. After all, we are always “running late.” We are always in a hurry. And we are so busy.

The forgiving roadway lulls us into a false sense of security. Vigilance and concentration wane on the forgiving road. Is it any wonder that today, we increasingly see motorists driving at high speeds with one hand, while putting on make-up, drinking coffee, or chatting on the cell phone with the other?

Since we tend to be busy and in a hurry, forgiving streets deliver lots of motorists who drive as fast as they can and “multi-task” while driving. Why? To save time.

The predictable result: An increase in crashes due to speeding, inattentiveness, and recklessness.

Ironically, motorist safety declines and driving skills atrophy, because the forgiving street conditions motorists to be less careful drivers, and lowers the need to maintain or improve driving skills. Increasingly, American motorists drive dangerously, and more ineptly.

Three Lanes vs Four Lanes

Some safety analysts point out that 3-lane roads are noticeably safer than 4-lane roads, in part because, when comparing 3 lanes to 4, average vehicle speeds are reduced, there is less variability in vehicle speeds, and there is less speeding. In addition, there is a significant reduction in what engineers call “conflict” points, and an increase in “sight distance” for turning and crossing traffic on a 3-lane versus 4-lane road (Welch, undated).

This is particularly important for senior citizens who are motorists, because fewer conflict points and increased sight distances means fewer decisions and judgements have to be made to enter or cross a 3-lane road.

Similarly, a 3-lane road reduces the street-crossing distance for pedestrians. Compared to a 4-lane road, a 3-lane can create “refuge” areas where a pedestrian can safely wait until there is a safe gap in traffic before crossing the other half of the street. A refuge is also created for motorists with 3 lanes.

A review of the research on this question raises significant questions as to whether wider roads are safer roads.

Fewer Travel Lanes

A study published in 2002 (Huang, Stewart, Zegeer, 2002) reported that in Oakland CA, a street carrying 24,000 trips per day was converted from four lanes to three. The number of annual crashes went from 81 before to 68 after. On another street in Oakland was narrowed, crashes went down 52 percent. In Minnesota, a road diet resulted in a 33-percent reduction in injury crashes. In Billings MT, a road diet resulted in 62 percent fewer crashes after travel lanes were removed. In Lewistown PA, removal of travel lanes saw the number of crashes drop to almost zero. Finally, these researchers found that in Seattle WA, a number of road diets were analyzed, and a 34-percent reduction in total crashes and a 7-percent drop in injury crashes was noted.

The Surface Transportation Policy Project (1999) released a study in 1999 that found a strong link between aggressive driving deaths and increased road capacity. Those living in states with the largest number of lane miles per capita were 65 percent more likely to die in an aggressive driving crash than in states with less lane miles per capita. Similarly, those metro areas that added the most lane miles over a five-year period had higher levels of aggressive driving deaths. See their 2003 report for additional information about how big roads are less safe.

The Iowa Department of Transportation (2001) has found that converting a four-lane undivided road to three lanes can improve safety while retaining an acceptable level of service. Their review of research found that when such conversions occurred, there was a reduction in average speeds, a significant reduction in speeding, and a substantial reduction in the total number of crashes.

According to Engwicht (1989), straighter, wider roads encourage greater speed. Accidents that do happen are therefore more severe, resulting in more injuries or a greater likelihood of death.

There is a large body of research which suggests that increasing the safety of a car or road simply encourages the driver to take greater risks. Drivers are willing to take a certain amount of risk in exchange for the benefit of faster traveling time. This risk is added to the safety limits of the car or road. The new safety features lull the driver into a new sense of security. Vigilance, concentration and attentiveness wane.

Welch (Welch, undated) conducted an analysis of converting a two-lane road to a four-lane road in Ft. Madison IA. This conversion resulted in a 4 percent increase in traffic volume, a 4 percent increase in corridor travel delay, a 2.5 mph increase in mid-block 85th percentile speed, a 14 percent increase in accidents and an 88 percent increase in injuries. The report also found that traffic traveling more than 5 mph over speed limit increased from 0.5% to 4.2%.

Welch reports that in Billings MT, when a four-lane was converted to a three-lane road, the number of reported accidents decreased from 37 in the 20 months before to 14 in the 20 months after conversion. No increase in traffic delay was found.

Despite initial apprehension from the local community and its engineers, Welch indicates that a conversion from four lanes to three in Storm Lake IA (US 71) resulted in an observed improvement in safety (“an immediate large reduction in accidents”). The Iowa DOT Office of Transportation Safety has begun actively promoting conversion of four-lane roads to three-lane when a concern about safety is expressed. In Helena MT, an urban primary highway (US 12) was converted from four lanes to three. (City staff and other state staff engineers now support the conversion after observing an improvement in traffic operations and a reduction in accidents.) In a study conducted for the Minnesota DOT, it was found that the highest urban corridor accident rates are found on four-lane undivided roads. In fact, the collision rate was 35 percent higher than on urban three-lane roads. Howard Preston, who conducted the study, stated that he would convert most four-lane roads with less than 20,000 car trips per day to three-lane roads “in a heartbeat.”

In Duluth MN, a conversion from four lanes to three (21st Ave East) was initially opposed by many. After conversion, the Duluth News-Tribune editorial had this to say: “When Duluth officials announced they would convert busy 21st Avenue East…from four lanes to two, with a turn lane in the middle, some armchair analysts predicted it wouldn’t work. The News-Tribune Opinion page was among them. Well, it works. About everyone agrees-from city traffic officials to neighbors-that the change has eased congestion and reduced drivers’ speed making it safer for pedestrians…”

Frequently, according to Welch, emergency vehicles find it difficult to travel down four-lane roads. Emergency vehicles typically need to wait for traffic to move over to the curb lane to get out of the way. But a center two-way left-turn lane usually has less vehicle conflicts, and often produces less delay for emergency vehicles traveling down it.

Hoyle (1995) points out that widened roads are alleged to be safer roads based on data provided by those in favor of many road widenings. However, data showing a decrease in crashes per vehicle mile don’t take into account the fact that widened roads encourage extra car trips that would not have happened had the road not been widened. Widened roads also encourage longer trip lengths. When such factors are taken into account, crash rates per trip or per hour spent on the road remain nearly the same.

Michael Ronkin (2001) suggests that the most effective way to reduce vehicle speed is by reducing the number of road lanes. “With two lanes in each direction, regardless of width, a driver who wants to move faster than the car in front can get into the adjacent lane and pass. With one lane in each direction, the slowest car sets the pace for all cars behind it.” While driving in Boston recently, he found that “lanes are narrow, very narrow, but on multi-lane one-way streets, cars zipped along at incredibly high speeds for urban streets, around 40 MPH…”

Ronkin notes a great deal of misunderstanding among pedestrian advocates about the speeds. “Pedestrians are more threatened by the occasional car going much faster than reasonable, than by cars travelling at an average speed.” On multi-lane roads, “the crossing pedestrian has several threats and challenges: the possibility of a car going faster than the rest of traffic could be invisible as it is masked by another car, its speed may not be apparent to the pedestrian. That makes it very difficult to judge adequate gaps. With one lane in each direction, a gap is a gap.”

One of the most frequent types of fatal crashes “is the multiple threat-a driver stops to let pedestrian cross on a multi-lane road, and the pedestrian is struck (and usually killed) by a driver passing in the adjacent lane.” Ronkin points out that this type of crash is not possible if there is no adjacent lane.

For Ronkin, another important contributor to crashes, besides speed, is the “complexity” involved in crossing a street. After analyzing a great many fatal crashes, he concludes that many of those crashes presented both the pedestrian and the driver with a relatively complex situation. According to Ronkin, “there just wasn’t enough time for both parties to react to an unforeseen event.” He concludes by pointing out the importance, in designing a road crossing, of creating an environment that that minimizes the number of decisions that must be made simultaneously..

In sum, Ronkin indicates that there have been “demonstrated reductions in crashes” when a road had lanes removed-convincingly so.

Narrow Lanes

Joseph R. Molinaro (1991) reports that wider travel lanes are more dangerous because they encourage higher-speed driving. Larger neighborhood collector streets work well with only 26 feet of width, and smaller neighborhood streets are safe at 20-24 feet. He also points out that residential streets should use tighter turns in order to force slower motorist speeds. With a smaller turn radius, motorists are more likely to come to a full stop than a more dangerous rolling stop.

The ITE Transportation Planning Council Committee (ITE, undated) cites the American Association of State Highway Officials, which found that “‘[t]he number of accidents increases with an increase in the number of decisions required by the driver.’ A corollary to this truism is that the actual and potential effects of each driver-decision become more significant as the speed of the particular motor vehicle increases.”

It is quite common for engineers to design a road for the rare large truck. Such design requires large turning radii and wide travel lanes. These relatively large dimensions far exceed those of passenger cars most common on residential streets. The overscaled design of these roads encourage faster passenger car speeds by the most frequent motor vehicles on these roads.

“Clearly, reducing the width of a street,” according to ITE, “has the effect of reducing vehicular speeds.”

The Conservation Law Foundation (1995) finds that vehicle speeds increase when roads are widened because there is an extra “safety cushion” provided by the increased lateral distances and increased sight distances. Psychologically, the wider road tells the motorist that it is safer to speed up, and since motorists tend to drive at the fastest speed they feel safe at, faster speeds are seen on wider roads with a higher perceived “safety cushion.” In addition, the field of vision of the motorist shrinks as speed increases, which reduces the ability of the motorist to see things (such as cars or pedestrians) that are ahead.

The Foundation also points out that designing for faster driving speeds, while possibly reducing the frequency of crashes, also increase the severity of car crashes.

Swift, Painter, and Goldstein (1998) conducted a study that analyzed the safest street widths with regard to accident frequency. Their study found that “as street width widens, accidents per mile per year increases exponentially, and that the safest residential street width is 24 feet (curb face).”

Indeed, crash rates were 18 times higher on 48-foot wide streets than on 24-foot wide streets.

The authors concluded, in part, by calling for a re-evaluation of public safety. That local governments recognize that the chance of injury or death due to, say, a neighborhood fire, is quite small compared to the much higher probability of injury or death in a neighborhood due to speeding traffic. That the reduced number of injuries or deaths resulting from wide streets and allegedly faster fire truck response time is tiny in comparison to the comparatively large number of injuries or deaths that occur due to speeding cars-a problem that increases in frequency due to widened streets. The local government should “ask if it is better to reduce dozens of potential vehicle accidents, injuries and deaths [through the creation of more modest streets], or provide wide streets for no apparent benefit to fire-related injuries or deaths.”

Even if more modest streets increased fire injury risks slightly (a problem not found by the study), modest streets would still be safer than wide streets because the risk of car injuries is so much higher than fire injuries.

In other words, by focusing public safety on life safety, rather than fire safety, a much larger number of community injuries and deaths can be managed and perhaps reduced.

A large number of firefighters are starting to understand that over-sized streets have resulted in streets that are not safe for families, while providing few, if any, benefits regarding fire safety and emergency response times, according to Siegman (2002).

Siegman relates a story from Dan Burden, a colleague who works in the field of safe street design:

While in Honolulu last week doing two school traffic calming charrettes our team had two tragic nights. In both cases a squad of firemen were with us for the evening, learning about and giving good input into traffic calming their neighborhoods. They had their truck with them in case they received a call. When asked by a member of the audience what they thought of the traffic calming plan the Captain said that they rarely, if ever, can expect a fire in the area….and that their concern is to lessen the speeds on area roads so that they are protecting rather than rescuing lives. They had good reason to say this … during the evening the firemen were called out to respond to a pedestrian tragedy several blocks from our meeting room, and in our project site.

The next school traffic calming meeting we again had four firemen, and their apparatus. We had just settled them down to a design table to design traffic calming solutions when they leaped up to attend a call. They, too, came back before the meeting was over. They had provided first assistance for a head-on crash of two motorists.

The meeting ended at 9:00. At 9:05 a bicyclist was hit (and presumably attended by these firemen). The cyclist was a star athlete on the University of Honolulu campus. She was killed one block from our school, in one of our crosswalks.

“Many firefighters,” according to Siegman, “realize that traffic crashes are a far greater hazard in our communities than fires, because they so often have to pick up the pieces.”

Siegman reminds us that “for every one person killed in a fire, more than eleven die in traffic crashes. And that for every one person injured by fire, 148 are injured in traffic crashes.”

A great many firefighters also tell us that fire truck response time does not depend simply on the width of a street.

For example, Siegman tells us that fire departments know that response time is a product of the speed of travel and the distance from the firehouse.

When streets are walkable and connected as they were in traditionally designed neighborhoods, they “usually allow far more direct routing than disconnected cul-de-sac designs.” Even when narrow (or “skinny”), the connected streets, Siegman points out, “can often deliver equal or better response times.” Connected streets also reduce the probability of traffic congestion, and congestion slows response times. “That understanding,” notes Siegman, “is apparently not yet reflected in fire codes, which discuss street width, but…have no specifications whatsoever on directness of routing, or distance from home to the arterial, or to the fire station.”

Siegman points out that a number of other fire departments are “no longer ordering U.S.-made fire engines, choosing instead the more maneuverable European models, which work well with smaller, safer, pedestrian-friendly street designs.”

According to Siegman, “we aren’t yet at the stage where all firefighters have excellent training in street design and traffic safety.” He wonders “how many communities still design their streets and intersections to accommodate the largest fire truck in the fleet, without having weighed pedestrian safety effects as part of the truck purchase.”

In conclusion, Siegman presents us with the following eye-opening statistics for fire and traffic fatalities and injuries in 1999 in the United States. In that year, “3,570 civilian (i.e. non-firefighter)” fire deaths occurred, and 21,875 civilians were injured. In addition, 112 fire fighters died while on duty-11 of them in traffic crashes. He also reports that “41,611 people were killed and 3,236,000 people were injured in the estimated 6,279,000 police-reported motor vehicle traffic crashes. 4,188,000 crashes involved property damage only.”

As reported by Finch (1994) and Preston (1995), every one mph reduction in traffic speed, in general, reduces vehicle collisions by five percent, and reduces fatalities to an even greater extent.

Narrowing travel lanes made things safer unless the narrowing was done to accommodate more travel lanes, according to a report from the Transportation Research Board (1994).

References Cited

Conservation Law Foundation. Take Back Your Streets. Boston MA. May 1995.

Engwicht, D. (ed.) Traffic Calming: The Solution to Urban Traffic and a New Vision for Neighborhood Livability. 1989.

Finch, D.J., Kompfner, P., Lockwood, C.R., Maycock, G. Speed, Speed Limits and Accidents. Transport Research Laboratory (Crowthorne, UK), Report 58, 1994.

Hoyle, C. Traffic Calming. American Planning Association. Planning Advisory Service Report Number 456. 1995.

Huang, H.F., Stewart, J.R. and Zegeer, C.V. Evaluation of Lane Reduction “Road Diet” Measures on Crashes and Injuries. Transportation Research Record 1784: 80-90. 2002.

Iowa Department of Transportation. Guidelines for the Conversion of Urban 4-lane Undivided Roadways to 3-lane Two-Way Left-turn Lane Facilities. April 2001.

ITE Transportation Planning Council Committee, Traditional Neighborhood Development: Street Design Guidelines. 5P-8. Undated.

Molinaro, J.R. Rethinking Residential Streets. Planning Commissioners Journal. Vol. 1:1. November/December 1991.

Preston, B. “Cost Effective Ways to Make Walking Safer for Children and Adolescents,” Injury Prevention, 1995, pp. 187-190.

Ronkin, M. Pedestrian & Bicycle Program Manager, Oregon Department of Transportation. March 27, 2001.

Siegman, P. Siegman & Associates, Town & Transportation Planning, 260 Palo Alto Avenue, Palo Alto, CA 94301. August 4, 2002 email submitted to a Dan Burden/Walkable Communities internet discussion group.

Surface Transportation Policy Project. Aggressive Driving. Washington DC. April 1999.

Swift, P., Painter, D. and Goldstein M. Residential Street Typology and Injury Accident Frequency. Copyright Peter Swift, Swift and Associates. 1998.

Transportation Research Board. Low-volume rural roads (Roadway Widths for Low-Traffic-Volume Roads). Transportation Research Board. NR362, 1994.

Welch, T.M. The Conversion of Four-Lane Undivided Urban Roadways to Three-Lane Facilities. Transportation Research Board. TRB Circular E-C019: Urban Street Symposium. Undated.

 

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Filed under New Urbanism: Timeless, Traditional, Walkable Design, Traffic Congestion, Visioning

Bigger Roads are Less Safe (despite what your traffic engineer says)

Dom Nozzi, AICP

In a great many cases, “improved safety” is a reason cited as a rationale for adding travel lanes to a road (“widening” a road). Indeed, because “improved safety” is a “moral high ground” argument (i.e., the argument should be accepted for ethical reasons), the safety rationale is perhaps the most common reason given for why a road “must” be widened.

In effect, public policy makers, when confronted with the “public safety” justification, are forced into an uncomfortable position when a decision must be made to widen or not widen a road: Either agree to the widening, or take a position that seems to suggest an uncaring attitude toward public safety.

It comes as no surprise that a large number of decision-makers are persuaded solely on the basis of the public safety argument.

Because road widenings are enormously expensive, speed up car traffic, and can profoundly worsen quality of life as well as accelerate strip commercial development and urban sprawl, we must be certain that road widenings do, in fact, deliver on the promise of dramatically improved safety.

The Forgiving Road

The “Forgiving Road” is a road that “forgives” a motorist when a driving mistake is made. That is, being reckless, or driving at high-speeds, or driving inattentively is not followed by the “punishment” of consequences such as crashing into something on the side of the road. For several decades, we have designed forgiving roads. We have been pulling buildings, parked cars, pedestrians, bicyclists, trees and other “obstructions” away from the sides of roads so that even an unskilled motorist can travel at high speeds without crashing into something.

The forgiving road was thought to be a way to promote “safety”(the hidden agenda, for many, was to promote high-speed travel by large volumes of car traffic).

Of course-human nature being what it is-such a design encourages reckless, high-speed, inattentive driving because human psychology compels us to tend to drive at the highest speed that still feels safe. After all, we are always “running late.” We are always in a hurry. And we are so busy.

The forgiving roadway lulls us into a false sense of security. Vigilance and concentration wane on the forgiving road. Is it any wonder that today, we increasingly see motorists driving at high speeds with one hand, while putting on make-up, drinking coffee, or chatting on the cell phone with the other?

Since we tend to be busy and in a hurry, forgiving streets deliver lots of motorists who drive as fast as they can and “multi-task” while driving. Why? To save time.

The predictable result: An increase in crashes due to speeding, inattentiveness, and recklessness.

Ironically, motorist safety declines and driving skills atrophy, because the forgiving street conditions motorists to be less careful drivers, and lowers the need to maintain or improve driving skills. Increasingly, American motorists drive dangerously, and more ineptly.

Three Lanes vs Four Lanes

Some safety analysts point out that 3-lane roads are noticeably safer than 4-lane roads, in part because, when comparing 3 lanes to 4, average vehicle speeds are reduced, there is less variability in vehicle speeds, and there is less speeding. In addition, there is a significant reduction in what engineers call “conflict” points, and an increase in “sight distance” for turning and crossing traffic on a 3-lane versus 4-lane road (Welch, undated).

This is particularly important for senior citizens who are motorists, because fewer conflict points and increased sight distances means fewer decisions and judgements have to be made to enter or cross a 3-lane road.

Similarly, a 3-lane road reduces the street-crossing distance for pedestrians. Compared to a 4-lane road, a 3-lane can create “refuge” areas where a pedestrian can safely wait until there is a safe gap in traffic before crossing the other half of the street. A refuge is also created for motorists with 3 lanes.

A review of the research on this question raises significant questions as to whether wider roads are safer roads.

Fewer Travel Lanes

A study published in 2002 (Huang, Stewart, Zegeer, 2002) reported that in Oakland CA, a street carrying 24,000 trips per day was converted from four lanes to three. The number of annual crashes went from 81 before to 68 after. On another street in Oakland was narrowed, crashes went down 52 percent. In Minnesota, a road diet resulted in a 33-percent reduction in injury crashes. In Billings MT, a road diet resulted in 62 percent fewer crashes after travel lanes were removed. In Lewistown PA, removal of travel lanes saw the number of crashes drop to almost zero. Finally, these researchers found that in Seattle WA, a number of road diets were analyzed, and a 34-percent reduction in total crashes and a 7-percent drop in injury crashes was noted.

The Surface Transportation Policy Project (1999) released a study in 1999 that found a strong link between aggressive driving deaths and increased road capacity. Those living in states with the largest number of lane miles per capita were 65 percent more likely to die in an aggressive driving crash than in states with less lane miles per capita. Similarly, those metro areas that added the most lane miles over a five-year period had higher levels of aggressive driving deaths. See their 2003 report for additional information about how big roads are less safe.

The Iowa Department of Transportation (2001) has found that converting a four-lane undivided road to three lanes can improve safety while retaining an acceptable level of service. Their review of research found that when such conversions occurred, there was a reduction in average speeds, a significant reduction in speeding, and a substantial reduction in the total number of crashes.

According to Engwicht (1989), straighter, wider roads encourage greater speed. Accidents that do happen are therefore more severe, resulting in more injuries or a greater likelihood of death.

There is a large body of research which suggests that increasing the safety of a car or road simply encourages the driver to take greater risks. Drivers are willing to take a certain amount of risk in exchange for the benefit of faster traveling time. This risk is added to the safety limits of the car or road. The new safety features lull the driver into a new sense of security. Vigilance, concentration and attentiveness wane.

Welch (Welch, undated) conducted an analysis of converting a two-lane road to a four-lane road in Ft. Madison IA. This conversion resulted in a 4 percent increase in traffic volume, a 4 percent increase in corridor travel delay, a 2.5 mph increase in mid-block 85th percentile speed, a 14 percent increase in accidents and an 88 percent increase in injuries. The report also found that traffic traveling more than 5 mph over speed limit increased from 0.5% to 4.2%.

Welch reports that in Billings MT, when a four-lane was converted to a three-lane road, the number of reported accidents decreased from 37 in the 20 months before to 14 in the 20 months after conversion. No increase in traffic delay was found.

Despite initial apprehension from the local community and its engineers, Welch indicates that a conversion from four lanes to three in Storm Lake IA (US 71) resulted in an observed improvement in safety (“an immediate large reduction in accidents”). The Iowa DOT Office of Transportation Safety has begun actively promoting conversion of four-lane roads to three-lane when a concern about safety is expressed. In Helena MT, an urban primary highway (US 12) was converted from four lanes to three. (City staff and other state staff engineers now support the conversion after observing an improvement in traffic operations and a reduction in accidents.) In a study conducted for the Minnesota DOT, it was found that the highest urban corridor accident rates are found on four-lane undivided roads. In fact, the collision rate was 35 percent higher than on urban three-lane roads. Howard Preston, who conducted the study, stated that he would convert most four-lane roads with less than 20,000 car trips per day to three-lane roads “in a heartbeat.”

In Duluth MN, a conversion from four lanes to three (21st Ave East) was initially opposed by many. After conversion, the Duluth News-Tribune editorial had this to say: “When Duluth officials announced they would convert busy 21st Avenue East…from four lanes to two, with a turn lane in the middle, some armchair analysts predicted it wouldn’t work. The News-Tribune Opinion page was among them. Well, it works. About everyone agrees-from city traffic officials to neighbors-that the change has eased congestion and reduced drivers’ speed making it safer for pedestrians…”

Frequently, according to Welch, emergency vehicles find it difficult to travel down four-lane roads. Emergency vehicles typically need to wait for traffic to move over to the curb lane to get out of the way. But a center two-way left-turn lane usually has less vehicle conflicts, and often produces less delay for emergency vehicles traveling down it.

Hoyle (1995) points out that widened roads are alleged to be safer roads based on data provided by those in favor of many road widenings. However, data showing a decrease in crashes per vehicle mile don’t take into account the fact that widened roads encourage extra car trips that would not have happened had the road not been widened. Widened roads also encourage longer trip lengths. When such factors are taken into account, crash rates per trip or per hour spent on the road remain nearly the same.

Michael Ronkin (2001) suggests that the most effective way to reduce vehicle speed is by reducing the number of road lanes. “With two lanes in each direction, regardless of width, a driver who wants to move faster than the car in front can get into the adjacent lane and pass. With one lane in each direction, the slowest car sets the pace for all cars behind it.” While driving in Boston recently, he found that “lanes are narrow, very narrow, but on multi-lane one-way streets, cars zipped along at incredibly high speeds for urban streets, around 40 MPH…”

Ronkin notes a great deal of misunderstanding among pedestrian advocates about the speeds. “Pedestrians are more threatened by the occasional car going much faster than reasonable, than by cars travelling at an average speed.” On multi-lane roads, “the crossing pedestrian has several threats and challenges: the possibility of a car going faster than the rest of traffic could be invisible as it is masked by another car, its speed may not be apparent to the pedestrian. That makes it very difficult to judge adequate gaps. With one lane in each direction, a gap is a gap.”

One of the most frequent types of fatal crashes “is the multiple threat-a driver stops to let pedestrian cross on a multi-lane road, and the pedestrian is struck (and usually killed) by a driver passing in the adjacent lane.” Ronkin points out that this type of crash is not possible if there is no adjacent lane.

For Ronkin, another important contributor to crashes, besides speed, is the “complexity” involved in crossing a street. After analyzing a great many fatal crashes, he concludes that many of those crashes presented both the pedestrian and the driver with a relatively complex situation. According to Ronkin, “there just wasn’t enough time for both parties to react to an unforeseen event.” He concludes by pointing out the importance, in designing a road crossing, of creating an environment that that minimizes the number of decisions that must be made simultaneously..

In sum, Ronkin indicates that there have been “demonstrated reductions in crashes” when a road had lanes removed-convincingly so.

Narrow Lanes

Joseph R. Molinaro (1991) reports that wider travel lanes are more dangerous because they encourage higher-speed driving. Larger neighborhood collector streets work well with only 26 feet of width, and smaller neighborhood streets are safe at 20-24 feet. He also points out that residential streets should use tighter turns in order to force slower motorist speeds. With a smaller turn radius, motorists are more likely to come to a full stop than a more dangerous rolling stop.

The ITE Transportation Planning Council Committee (ITE, undated) cites the American Association of State Highway Officials, which found that “‘[t]he number of accidents increases with an increase in the number of decisions required by the driver.’ A corollary to this truism is that the actual and potential effects of each driver-decision become more significant as the speed of the particular motor vehicle increases.”

It is quite common for engineers to design a road for the rare large truck. Such design requires large turning radii and wide travel lanes. These relatively large dimensions far exceed those of passenger cars most common on residential streets. The overscaled design of these roads encourage faster passenger car speeds by the most frequent motor vehicles on these roads.

“Clearly, reducing the width of a street,” according to ITE, “has the effect of reducing vehicular speeds.”

The Conservation Law Foundation (1995) finds that vehicle speeds increase when roads are widened because there is an extra “safety cushion” provided by the increased lateral distances and increased sight distances. Psychologically, the wider road tells the motorist that it is safer to speed up, and since motorists tend to drive at the fastest speed they feel safe at, faster speeds are seen on wider roads with a higher perceived “safety cushion.” In addition, the field of vision of the motorist shrinks as speed increases, which reduces the ability of the motorist to see things (such as cars or pedestrians) that are ahead.

The Foundation also points out that designing for faster driving speeds, while possibly reducing the frequency of crashes, also increase the severity of car crashes.

Swift, Painter, and Goldstein (1998) conducted a study that analyzed the safest street widths with regard to accident frequency. Their study found that “as street width widens, accidents per mile per year increases exponentially, and that the safest residential street width is 24 feet (curb face).”

Indeed, crash rates were 18 times higher on 48-foot wide streets than on 24-foot wide streets.

The authors concluded, in part, by calling for a re-evaluation of public safety. That local governments recognize that the chance of injury or death due to, say, a neighborhood fire, is quite small compared to the much higher probability of injury or death in a neighborhood due to speeding traffic. That the reduced number of injuries or deaths resulting from wide streets and allegedly faster fire truck response time is tiny in comparison to the comparatively large number of injuries or deaths that occur due to speeding cars-a problem that increases in frequency due to widened streets. The local government should “ask if it is better to reduce dozens of potential vehicle accidents, injuries and deaths [through the creation of more modest streets], or provide wide streets for no apparent benefit to fire-related injuries or deaths.”

Even if more modest streets increased fire injury risks slightly (a problem not found by the study), modest streets would still be safer than wide streets because the risk of car injuries is so much higher than fire injuries.

In other words, by focusing public safety on life safety, rather than fire safety, a much larger number of community injuries and deaths can be managed and perhaps reduced.

A large number of firefighters are starting to understand that over-sized streets have resulted in streets that are not safe for families, while providing few, if any, benefits regarding fire safety and emergency response times, according to Siegman (2002).

Siegman relates a story from Dan Burden, a colleague who works in the field of safe street design:

While in Honolulu last week doing two school traffic calming charrettes our team had two tragic nights. In both cases a squad of firemen were with us for the evening, learning about and giving good input into traffic calming their neighborhoods. They had their truck with them in case they received a call. When asked by a member of the audience what they thought of the traffic calming plan the Captain said that they rarely, if ever, can expect a fire in the area….and that their concern is to lessen the speeds on area roads so that they are protecting rather than rescuing lives. They had good reason to say this … during the evening the firemen were called out to respond to a pedestrian tragedy several blocks from our meeting room, and in our project site.

The next school traffic calming meeting we again had four firemen, and their apparatus. We had just settled them down to a design table to design traffic calming solutions when they leaped up to attend a call. They, too, came back before the meeting was over. They had provided first assistance for a head-on crash of two motorists.

The meeting ended at 9:00. At 9:05 a bicyclist was hit (and presumably attended by these firemen). The cyclist was a star athlete on the University of Honolulu campus. She was killed one block from our school, in one of our crosswalks.

“Many firefighters,” according to Siegman, “realize that traffic crashes are a far greater hazard in our communities than fires, because they so often have to pick up the pieces.”

Siegman reminds us that “for every one person killed in a fire, more than eleven die in traffic crashes. And that for every one person injured by fire, 148 are injured in traffic crashes.”

A great many firefighters also tell us that fire truck response time does not depend simply on the width of a street.

For example, Siegman tells us that fire departments know that response time is a product of the speed of travel and the distance from the firehouse.

When streets are walkable and connected as they were in traditionally designed neighborhoods, they “usually allow far more direct routing than disconnected cul-de-sac designs.” Even when narrow (or “skinny”), the connected streets, Siegman points out, “can often deliver equal or better response times.” Connected streets also reduce the probability of traffic congestion, and congestion slows response times. “That understanding,” notes Siegman, “is apparently not yet reflected in fire codes, which discuss street width, but…have no specifications whatsoever on directness of routing, or distance from home to the arterial, or to the fire station.”

Siegman points out that a number of other fire departments are “no longer ordering U.S.-made fire engines, choosing instead the more maneuverable European models, which work well with smaller, safer, pedestrian-friendly street designs.”

According to Siegman, “we aren’t yet at the stage where all firefighters have excellent training in street design and traffic safety.” He wonders “how many communities still design their streets and intersections to accommodate the largest fire truck in the fleet, without having weighed pedestrian safety effects as part of the truck purchase.”

In conclusion, Siegman presents us with the following eye-opening statistics for fire and traffic fatalities and injuries in 1999 in the United States. In that year, “3,570 civilian (i.e. non-firefighter)” fire deaths occurred, and 21,875 civilians were injured. In addition, 112 fire fighters died while on duty-11 of them in traffic crashes. He also reports that “41,611 people were killed and 3,236,000 people were injured in the estimated 6,279,000 police-reported motor vehicle traffic crashes. 4,188,000 crashes involved property damage only.”

As reported by Finch (1994) and Preston (1995), every one mph reduction in traffic speed, in general, reduces vehicle collisions by five percent, and reduces fatalities to an even greater extent.

Narrowing travel lanes made things safer unless the narrowing was done to accommodate more travel lanes, according to a report from the Transportation Research Board (1994).

References Cited

Conservation Law Foundation. Take Back Your Streets. Boston MA. May 1995.

Engwicht, D. (ed.) Traffic Calming: The Solution to Urban Traffic and a New Vision for Neighborhood Livability. 1989.

Finch, D.J., Kompfner, P., Lockwood, C.R., Maycock, G. Speed, Speed Limits and Accidents. Transport Research Laboratory (Crowthorne, UK), Report 58, 1994.

Hoyle, C. Traffic Calming. American Planning Association. Planning Advisory Service Report Number 456. 1995.

Huang, H.F., Stewart, J.R. and Zegeer, C.V. Evaluation of Lane Reduction “Road Diet” Measures on Crashes and Injuries. Transportation Research Record 1784: 80-90. 2002.

Iowa Department of Transportation. Guidelines for the Conversion of Urban 4-lane Undivided Roadways to 3-lane Two-Way Left-turn Lane Facilities. April 2001.

ITE Transportation Planning Council Committee, Traditional Neighborhood Development: Street Design Guidelines. 5P-8. Undated.

Molinaro, J.R. Rethinking Residential Streets. Planning Commissioners Journal. Vol. 1:1. November/December 1991.

Preston, B. “Cost Effective Ways to Make Walking Safer for Children and Adolescents,” Injury Prevention, 1995, pp. 187-190.

Ronkin, M. Pedestrian & Bicycle Program Manager, Oregon Department of Transportation. March 27, 2001.

Siegman, P. Siegman & Associates, Town & Transportation Planning, 260 Palo Alto Avenue, Palo Alto, CA 94301. August 4, 2002 email submitted to a Dan Burden/Walkable Communities internet discussion group.

Surface Transportation Policy Project. Aggressive Driving. Washington DC. April 1999.

Swift, P., Painter, D. and Goldstein M. Residential Street Typology and Injury Accident Frequency. Copyright Peter Swift, Swift and Associates. 1998.

Transportation Research Board. Low-volume rural roads (Roadway Widths for Low-Traffic-Volume Roads). Transportation Research Board. NR362, 1994.

Welch, T.M. The Conversion of Four-Lane Undivided Urban Roadways to Three-Lane Facilities. Transportation Research Board. TRB Circular E-C019: Urban Street Symposium. Undated.

 

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Filed under Bicycling, New Urbanism: Timeless, Traditional, Walkable Design, Traffic Congestion

Newspaper Editor Sings Praises of Narrowing Main Street in Florida

By Ron Cunningham, The Gainesville (FL) Sun

Sunday, June 23, 2002

 

Bringing back University Avenue

“The city shall encourage University Avenue to become Gainesville’s ‘Signature Street,’ as a potential magnet for high-quality development. The City’s investment in infrastructure on this corridor, from West 38th Street to Waldo Road, shall be the highest priority in the city.”

– Objective 3.2 in the Urban Design element of Gainesville’s Comprehensive Plan.

Take a walk along Gainesville’s “Signature Street,” in search of “high quality” development. Start at the entrance of the University of Florida, at 13th Street, and walk north toward 6th Street.

Pass the garish orange-and-blue gas station and convenience store. Stroll by the designer nail salons, tattoo parlors and body piercing emporiums that seem to go in and out of business with revolving-door regularity. If you want to pawn a watch, or if you are in the market for exotic lingerie, handcuffs, a gas mask or a samurai sword, you’ve come to the right place. Ditto if you need gasoline, rolling papers, used clothing, lottery tickets, a lube job or a U-Haul rental.

Notice the empty store fronts, eight of them at last count. Drop into one of the three or four popular restaurants that have withstood the test of time despite the street’s seemingly inhospitable business environment.

Take in the fast-food joints, the buy, sell or trade CD shops, pawn shops, the occasional bookstore and the army surplus store.

Notice the scrawny street trees and the weeds poking stubbornly up out of the cracks of the narrow gray cement sidewalk. Try to ignore the litter and cigarette butts, but do admire the graffiti that decorates many of the building fronts, street light poles, newspaper racks and street signs.

Observe the unkempt appearance of many of the building facades – the discolored awning here, the fading paint there. Notice how some businesses have plastered over their windows with come-on ads touting discount prices, while others have taken pains to maintain an attractive storefront and even tidy landscaping.

Sit on one of the few public benches and take in the street life. Watch the competition for finite sidewalk space between the occasional pedestrian and the cyclist who, having no death-wish, declines to ride on the street. Dig into your pockets for change as the panhandler on the rusty bicycle approaches.

And absorb the noise of the street: that nearly continuous roar of the traffic that makes normal conversation on the sidewalk difficult. Watch the automobiles, pickups, SUVs and even semi-tractor trailers jockey for position on four-lane University – very often at speeds quite in excess of the posted 30 mph.

And then recall the words of South Miami town planning consultant Victor Dover three years ago, during the final presentation to the City Commission of Dover, Kohl and Partners’ plan to turn University Avenue into Gainesville’s “signature” street.

That study focused specifically on transforming University Avenue between 6th Street to 13th Street into Gainesville’s gateway to the University of Florida.

“Every city needs great buildings and great public places,” Dover told the commissioners. “Great cities are defined more than anything else by their great streets. Great streets are the public rooms of a city. And they are almost always a result of careful planning.”

Last Monday, Dan Burden, nationally renown consultant with Walkable Communities Inc. took that stroll. He surveyed the narrow sidewalks and marginal nature of many of the businesses, doled out change to the panhandler and snapped a few photos along the way.

Long based in High Springs, Burden spends most of this time helping dysfunctional cities around the country turn traffic-congested, and usually blighted, corridors into pedestrian- and bicycle-friendly walkable town centers.

“This is a street that has no sense of itself, it could be any suburban roadway in the country,” Burden said. “It really hasn’t healed itself in 20 years. . . . There are businesses here, but it’s not the highest and best use of University Avenue. People are not investing in their buildings, they’re run-down. It’s not a good mix of uses.”

When he gave his presentation for transforming University Avenue, in 1999, Dover cautioned the commission: “It’s only going to get more difficult as you wait.” That has turned out to be a prescient statement.

The Metropolitan Transportation and Planning Organization has put the redesigning and narrowing of University Avenue on its long-range Transportation Improvement List. But the project won’t work its way to the top of the list until about 2010. And even then, it is uncertain that funding will be available to reduce four lanes of traffic down to two lanes and a turning lane, to provide on-street parking, to widen the sidewalks and make other improvements.

And then there is the question of political and public support. Already, a popular backlash has developed against the notion of narrowing University Avenue. In the last election, the last two city commissioners to vote for the Dover, Kohl recommendations left office. Pegeen Hanrahan, stepped down due to term limits; John Barrow was not re-elected.

Both those former commissioners were bullish on remaking University Avenue to “calm traffic” and be more inviting for pedestrians, bicyclists and investment. Both have since been replaced by commissioners who ran in opposition to reducing lanes on University Avenue.

One on them, Commissioner Tony Domenech, ran radio ads proclaiming that it was “insane” to eliminate lanes on Gainesville’s major east-west corridor.

“I conceptually have difficulty understanding how you can move people from Point A to Point B by restricting the amount of flow,” Domenech said recently. “It’s just like a pipe – there’s a certain volume that goes through the pipe, and when you restrict the pipe, you increase the pressure going through there.”

However, a traffic analysis completed by Orlando traffic engineer Walter Kulash shows that reducing lanes on University Avenue would not create the traffic gridlock that many opponents fear.

Traffic counts record some 26,500 vehicles a day on University Avenue near 13th Street, dwindling to about 18,500 vehicles per day east of Main Street. Kulash’s analysis showed that 1,740 vehicles an hour could be accommodated on a two-lane University Avenue.

That count is exceeded on University by, at most, about 200 vehicles per hour between noon and 6 p.m. on weekdays. Some of that additional traffic will elect to divert to other routes, Kulash predicted, but even if it does not, motorists “will experience an additional 20- to 30-second delay – during the peak period only – at each signal on University Avenue between NW 6th Street and NW 12th St. This makes for a total time loss of 1 to 2 minutes along the route.”

Gainesville’s street grid system also provides numerous alternative routes for motorists on “short trips to and from University, downtown and the surrounding neighborhoods,” Kulash said.

Because University Avenue is a state highway, SR 26, the consultant also mapped out several potential east-west “regional bypasses” that could be used to reroute through-traffic away from University Avenue; the most likely bypass being Archer Road to Williston Road to E. University.

“People are so convinced that traffic is like water; it has to go somewhere,” Kulash said recently. “But we know that once an area becomes vibrant, some traffic disappears. People change their destinations very quickly. What we see when an area becomes viable is that people want to live there and spend time there instead of driving 8 miles out to visit a discount store.”

Among the skeptics of the contention that University Avenue can function just as well as a two-lane road is Aage Schroder, regional secretary of the Florida Department of Transportation.

“We don’t think it’s a particularly good idea,” he said. “There’s no way to mitigate the impact on traffic. I’m sure that (reducing lanes) is not the consensus of the community. It’s the consensus of the few.”

If the last election is an indicator, Schroder is probably right. Even among people who do business on University Avenue there is disagreement over changing the street.

“We can’t even greet our customers until they’re inside and the doors are closed,” because of the traffic noise, says Dotty Faibisy, owner of Wild Iris Books. “We’ve got traffic booming up and down University. It’s just not a friendly place for people or bicyclists.”

But across the street, at Myrt’s News, Myrtle Gunter says “narrowing the street is a horrible thought. This is a major east-west connector. My customers can find a parking space when they want to come by for a newspaper.”

“They’ve got to do something,” says Nick Farah, who has owned Farah’s On the Avenue for 23 years. “We’re sitting here and semis are going down the street at 50 mph. I’ve seen a lot of people hurt out there. If not narrowing, they need to do something to calm the traffic.”

While any decision in regard to altering University Avenue may be years away, the city is planning to take several more immediate steps to try to make the avenue more attractive.

A University Avenue “Spruce Up Day,” to clean up pick up litter, remove graffiti and so on is planned for Aug. 2. In addition, the city has plans to pressure wash the sidewalks, paint decorative crosswalks at intersections, improve streetscaping and install more attractive street lighting, parking meter posts, benches and trash cans.

New design standards will also ensure that any future development will conform to the city’s vision to make University Gainesville’s “signature” street. And recently, the commission voted to spend $466,000 to help a Jackson- ville-based company, LB Jax Development, build West University Lofts, a $2.8 million mixed-use development at the intersection of 6th and University.

Chris Brown, a partner in that firm, was a city planner for Delray Beach when that coastal city made the decision to narrow a section of Atlantic Avenue as part of a wildly successful effort to revitalize Delray’s downtown area.

“What about two-lane roads as Main Streets?” Brown posed. “It’s been an economic miracle, the saving grace for retailing downtown. In the late 1980s, the merchants weren’t absolutely convinced, they didn’t even want to see trees on the street blocking their signs. But it really worked in Delray, everybody wants to shop there, and everybody wants to eat there.

“We’re looking forward to the day they beautify University Avenue,” he said. “I think it (University Lofts) will be viable either way, but probably real estate values will go way up if they do narrow the street.”

Traffic calming advocates argue that the city’s planned embellishments alone will do little to improve the commercial viability of University Avenue or to attract more pedestrians or bicyclists (read, customers) to the corridor.

“It’s not a matter of if you do it, but when,” said Burden, who has seen traffic calming pay economic benefits in cities all over the country.

Three essential elements to bringing back University, Burden and others say, are:

1. Wider sidewalks, adequate to support foot traffic, outdoor cafes, bicyclists and other activity. Currently, sidewalks on University are as narrow as 5 or 6 feet. The Dover, Kohl study recommends sidewalks of up to 15 feet in length.

2. On-street parking on both sides of the avenue, not only to accommodate motorists who wish to stop and shop, but also to provide a physical barrier between strollers on the sidewalk and moving traffic.

3. Fewer and narrower travel lanes to slow down traffic and to make it easier and safer for pedestrians to cross the street. Currently, the travel lanes on University are 12 feet wide, which Kulash calls “interstate highway standard.” The three-lane alternative envisions 11-foot lanes.

“No other business environment in Gainesville is saddling themselves with having 40 mph traffic 3 or 4 feet away from people who are out of their vehicles attempting to enter a business establishment,” Kulash told the commission. “Not even the strip malls put up with those kind of conditions.”

Ultimately, if Gainesville does decide to redesign University Avenue, it will likely first have to negotiate an agreement with the DOT to take over responsibility for the street. “We’re not interested in maintaining it if that’s the case,” Schroder said.

A similar transfer of control was arranged on Main Street, which in two years is scheduled to undergo lane reduction and other improvements from Depot Avenue to N. 8th Avenue. Advocates are hoping that the Main Street project will do exactly what it’s supposed to do – revitalize the street without creating traffic jams – and thereby build support for narrowing University Avenue.

“The way you win public acceptance is by having one great model that proves the world does not fall off its axis if you do this,” Burden said.

Sunday, June 23, 2002

Successful Main Street models

Scenes from an urban landscape:

Scene One: It is Mother’s Day, and Park Avenue is alive with people.

They stroll leisurely up and down one of Florida’s great “Main Streets.” They window-shop at The Gap, the Banana Republic or one of the avenue’s other high-end retail stores. They lunch at the sidewalk cafes, or cross the street for a walk in the park; perhaps to watch a train pull into the Amtrak station.

On the street itself, a steady stream of traffic creeps along. Motorist patiently search for a gap in the wall of parked automobiles that separate pedestrians from motorists, or they duck into side streets looking for an available space. They want to get out of their SUVs and sedans and join the procession of strollers up and down the avenue; to see or to be seen in fashionable Winter Park.

Winter Park, home of Rollins College, is a green oasis of studied elegance in the middle of the unrelenting concrete and asphalt wasteland of suburban northeast Orlando. Hailed as one of Florida’s most “liveable cities,” the town long ago discovered that ambiance is a bankable commodity. Winter Park has some of the highest property values in Central Florida, and Park Avenue is surrounded by expensive homes, condos, townhouses and above-store apartments.

Scene two: It is Mother’s Day and Church Street Station is hanging on for dear life.

Church Street Station, in downtown Orlando, is a Disneyesque attempt to recreate from whole cloth a sort of faux-Bourbon Street atmosphere. It is located right next to I-4 for ease of access. Acres of parking is provided just a few steps away for the convenience of shoppers and night-life seekers. With its turn-of-the-century ambiance and theme park-like flavor, Church Street Station ought to be a consumer magnet in a town that survives on luring the tourists out of their rental cars and hotels and into yet another spending opportunity.

And yet, Church Street Station is on a downhill skid. Rosey O’Grady’s, for years the night-life anchor on the street is gone. The chain stores and restaurants are leaving, one by one. There are empty store fronts where T-shirt shops and souvenir emporiums used to be. Very few people wander about, and a handful of street vendors stand on the sidewalk, expectantly, as though still awaiting the onset of the business day.

Why does a Park Avenue thrive while a Church Street Station dies?

Well, for one thing, Disney and Universal Studios looked at Church Street Station, figured out that there was a market for adult night life that the giant theme parks weren’t capturing and then went after it. Competing with Park Avenue was another story.

“Church Street Station was always commercial tourism,” says Walter Kulash, senior traffic engineer for the Orlando-based community-planning firm of Glatting, Jackson, Kercher, Anglin, Lopez, Rinehart Inc. “Winter Park is a real town center. Church Street Station doesn’t get local people coming on a repeated basis; it didn’t get local people coming at all after awhile.”

Perhaps the lesson of Church Street Station is that you can’t build a pretend Main Street. For downtown commercial and entertainment centers to survive and thrive, they must look and function exactly like what they are supposed to be – the organic heart of the community, not just another roadside tourist attraction.

Florida’s best known and most successful Main Streets – Park Avenue, Miami’s Coconut Grove and South Beach, Palm Beach’s Worth Avenue and Key West’s Duval Street, to name a few – long ago learned the secret to survival in a state that has for half a century blindly embraced suburbanization as the dominant lifestyle: Invest in public infrastructure, pay careful attention to street-scaping and urban trees, adopt design standards that support the village-like character of downtown, and make sure the sidewalks are adequate for people to walk, dine, window shop and congregate.

And above all, get control of the traffic. Traffic is a Main Street killer.

Slow it down by design – with narrow streets, fewer travel lanes, roundabouts, landscaped traffic medians, on-street parking, raised intersections, speed bumps and other “traffic calming” techniques.

In fact, cities all over Florida have begun to “take back” their downtowns in recent years, following successful Main Street models like Winter Park, Coconut Grove and South Beach. From Sarasota to St. Petersburg to New Smyrna Beach to Clearwater to Hollywood, virtually all have adopted a variety of traffic calming policies designed to put automobiles in their place and bring people and investment back to long-neglected city cores.

Here are a few examples of cities that have taken back their downtowns:

FT. PIERCE – BACK TO THE FUTURE: “I grew up here . . . we belong here,” says Jim Gately, from behind the counter of his popular sidewalk eatery Gately’s Grille at the corner of Orange Avenue and 2nd Street. “People had abandoned downtown for years, and now they’re coming back. And they’re not blowing by at 35 or 40 mph, either. They’re getting out of their cars and spending money.”

For three years, Gately has been doing a brisk business in Fort Pierce’s newly restored downtown, an area that has taken on the feel and flavor of the Mediterranean village that town fathers had begun to build in the good times of the 1920s – before the Florida land boom went bust.

Fort Pierce is a city of 20 square miles and 37,516 people. Located where Florida’s Turnpike meets I-95, it sits at the northern tip of the burgeoning Gold Coast megalopolis. A rather nondescript city of sprawling, unconnected subdivisions, Fort Pierce is also one of South Florida’s less affluent coastal communities.

But in 1995, city officials set out to rebuild an urban core that had long ago been dissected by U.S. 1, which funnels 40,000 autos a day through the heart of Fort Pierce. Over the course of dozens of community charettes and workshops, traffic calming emerged as an important component of revitalization.

To the east of U.S. 1, Orange Avenue, a three-lane, one-way high-speed road running into the heart of downtown, was converted to a two-lane, two-way street. To the west, Delaware Avenue, a once elegant street lined with stately oaks, was reduced from four-lanes to two lanes. Several other downtown corridors were also put on a “road diet.” Indian River Drive, a well-traveled road along the lagoon that connects to the beach, was fitted with a traffic circle at the intersection with Avenue A.

The roundabout – with its carved pink stone base and lushly landscaped center – is both an efficient way to move traffic through downtown and a popular “photo opportunity” spot for tourists. This in marked contrast to the ugly metal barrier that once blocked the view of the waterfront at that intersection as motorists backed up in all directions while waiting for the light to change.

“Multiple lanes don’t move traffic,” says Ramon Trias, Fort Pierce city planner. “All it does it stack traffic. The problem with the old traffic pattern was that it was dysfunctional.”

In addition to reconfiguring the roadways, Fort Pierce invested something like $20 million over six years – building a new downtown library and police substation, restoring the 1925 City Hall, and renovating the 1923 Sunrise Theater into a 1,200-seat cultural arts center. An abandoned high school on Delaware Avenue was turned into a magnet school for the arts. Such expenditures in turn generated more than $31 million in additional investments, and the downtown tax base has doubled.

With its red-brick sidewalks and stately palm tree-lined streets, downtown Fort Pierce has a low vacancy rate. And the street narrowings notwithstanding, some 1,500 workers and commuters move through downtown each day, not to mention 150,000 visitors a year.

“If traffic gets bad, people drive less,” says Trias. “Isn’t that logical?”

WEST PALM BEACH – MOVING BACK IN: Just a decade ago, West Palm Beach was an urban jungle at night.

Drug dealing and prostitution was the main commerce on historic Clematis Street. Not far away, several blocks of one-time crack houses had been razed, and the property abandoned. In 1993, Clematis Street had a 90 percent vacancy rate and property values running as low as $10 per square foot.

If you visit Clematis Street today, you can ride a free trolly up and down its 4,500-foot length past more than 80 restaurants and retail establishments. Property values have skyrocketed and expensive new residential developments have sprung up around it.

A colorful downtown plaza at its eastern terminus sports an amphitheater and a “dancing” fountain, where delighted children drench themselves under the watchful eyes of a city “fountain guard.” On Friday nights, thousands of people gather on the plaza for city-sponsored block parties.

And at the site of the former crack houses has risen City Place, an impressive $550 million mixed-used development of stores and restaurants, a multiplex movie theater and performing arts center, townhouses and rental apartments. City Place has attracted several major chain stores, including a Publix Super Market that, thanks to local design standards, looks like anything but a Publix.

A decade ago, West Palm Beach’s ability to finance public improvements was practically nonexistent. So the city went into traffic calming as a reclamation and economic development tool in a big way – aggressively narrowing lanes and redesigning streets to slow down traffic all over the city.

“The city was broke, and its physical environment was dilapidated,” senior city planners Tim Stillings and Ian Lockwood have written of West Palm’s experience. “West Palm Beach had much larger issues that required immediate attention beyond simply speeding, collisions and cut-through motor vehicle traffic. At the heart of many of its challenges were the negative effects of those vehicles in the city and past treatment of street environments.

“The evolution of traffic calming combined with the use of New Urbanist principles and a host of other initiatives allowed the city to begin its metamorphosis into a ‘masterpiece city.’ ”

Clematis Street, one-way with three travel lanes and two parking lanes, was converted back into a two-lane, two-way street with angle-parking on both sides of the street. City Place was likewise designed and constructed along New Urbanist principles, serviced by two-lane streets and on-street parallel parking. Soon, two other major downtown streets, Dixie Highway and Olive, will also be narrowed in an ongoing traffic-calming effort.

“Once Clematis Street was done, businesses started coming back downtown,” says Stillings. “It’s not only a better business climate but also a much nicer environment for people.”

As a result of the city’s revitalization efforts, people are moving back into downtown West Palm Beach. As much as any city in Florida, revitalized West Palm Beach is benefiting from the “empty-nest syndrome” as baby boomers whose children have left home are electing to leave the suburbs to spend their golden years in a more stimulating urban environment.

“The public realm is the connective tissue of our everyday world,” Nancy Graham, the former West Palm Beach mayor who led the downtown revitalization effort, once told a reporter. “Human scale must prevail over the needs of motor vehicles.”

STUART – NO SURRENDER TO DOT: For residents of Stuart, a former railroad town nestled in a tight peninsula on the St. Lucie River, the crises point occurred in 1988. That’s when the state Department of Transportation made hurricane evacuation plans that included construction of a new multi-lane bridge across the river, widening U.S. 1. and running it through the heart of this small but viable downtown.

“The DOT is an enormous, rich, self-righteous bureaucracy experienced in getting its way,” a little-known architect named Andres Duany told the city in a report that year. “You will have a battle, but it is one that must be fought.

“Remember, DOT in its single-minded pursuit of traffic flow has destroyed more American towns than General Sherman.”

Duany went on to become a founder of the New Urbanist movement, and Stuart went on to win its war against DOT. The new bridge was built and U.S. 1 improved, but in a way that bypassed, not gutted, downtown. Downtown Stuart today is a picturesque village of narrow, interesting, sometimes confusing streets lined with prosperous restaurants, gift shops, art galleries, a restored theater and night spots. It’s attraction as a destination is such that it is difficult to find a parking space downtown even on a weeknight. And some of the most expensive housing in Martin County is located on the edges of downtown.

“When you think about it, lack of parking is a great problem to have,” says City Planner Kim DeLaney. “It means people want to come here.”

Stuart’s renovations have all been designed to maintain downtown as a “walkable community.” Some 21,000 employees work within a two-mile radius of downtown. As many as eight freight trains a day come through the town center, and 8,000 vehicles move through downtown during the evening rush hour.

Traffic is heavy at such times, but not gridlocked. Stuart’s “Confusion Circle” – a much celebrated roundabout located where no fewer than six streets and a railroad crossing come together – somehow manages to keep traffic flowing more or less smoothly. Indeed, watching traffic move around the circle, one has difficulty imagining how the flow of traffic from that many converging streets could even be regulated by traffic signals.

“We do see a lot of accidents, but they’re all fender-benders, because nobody is driving too fast,” says Loretta Englishman, who works at an insurance agency located across the street from Confusion Circle.

“Once in a while you’ll see senior citizens go the wrong way on the circle, but people will usually just get out of their way.”

Only one street leading into downtown, Colorado Avenue, is wider than two lanes. It is visibly the least attractive and economically stagnant street in downtown, and the city is making plans to slow down traffic on Colorado in order to stimulate investment and attract people. The anticipation is that revitalizing Colorado will, in turn, help spark reinvestment in some of the less affluent residential streets that intersect it.

n LOS OLAS – PART-TIME CALMING: Los Olas Boulevard has always been an elegant avenue of expensive shops, fashionable galleries and offices. But the eastern shopping district of downtown Fort Lauderdale all but closed down at the end of the working day, and for much of the off-season, for that matter.

“Some merchants used to put up signs at the end of Memorial Day saying ‘Come back again next season,’ ” recalled former Fort Lauderdale City Manager George Hanbury. “You could roll a bowling ball down Los Olas after 5 p.m. and never touch anyone.”

Even as Fort Lauderdale’s downtown business district was undergoing a major economic revitalization, Los Olas remained an under-used corridor. These days, however, Los Olas is alive with people night and day. The city did two things to transform Los Olas into the city’s most popular nighttime and weekend destination.

“It was really simple,” said Emmett McTigue, a major downtown landowner. “They changed the ordinance to allow outside dining on the sidewalks, and they narrowed Los Olas from four lanes to two lanes and allowed on-street parking during the nights and weekends.”

Actually, it wasn’t as simple as that. City officials wanted to permanently reduce lanes on Los Olas; and they had traffic counts to support their contention that four lanes were unnecessary. But Los Olas is a county road that connects downtown to the beach, and county officials wouldn’t allow it.

In the end, the county compromised by allowing evening and weekend lane reduction, while maintaining four lanes during working hours.

The compromise made a huge difference in the life of the street. The transformation of the street via part-time traffic calming has brought considerable new private investment to the area, as more and more people want to live near downtown’s lively Los Olas.

“Most of the redevelopment effort has been private,” Hanbury said. “But the catalyst was outdoor dining and on-street parking.”

Similar success stories have been repeated all over Florida, in cities large and small – in Delray Beach, DeLand, Lake Worth, Boca Raton and elsewhere.

“There’s no way to refute it anymore, when it’s done right it works every time,” says Tom Flemming, who was Main Street coordinator when Delray Beach brought its downtown back, and who is now working to create a downtown in Oakland Park, a Broward County municipality that never had a city center.

“Downtowns can’t function with both the automobile and the pedestrian being the priority.”

Sunday, June 23, 2002

Speed kills (Main Streets)

I guess I ought to start by telling you about my first traffic ticket.

I was 19, it was a Saturday night, and I was cruising down Hollywood Boulevard in my rust-yellow ’54 Studebaker.

I was driving too fast, ran a red light, and one of Hollywood’s finest spotted me from about two blocks away and nailed me before I got halfway around Hollywood Circle.

In retrospect – 35 years worth of retrospect – all I can say in my defense is that I was young and stupid and under the influence of that most powerful of all American intoxicants . . . gasoline.

And by way of extenuating circumstances, I might add that at the time you could have fired a cannon down the middle of Hollywood Boulevard and not worried too much about hitting anybody.

That’s because the downtown Hollywood of my youth was pretty much a ghost town after dark. During the daytime, too, for that matter.

Oh, when I had been 7 or 8, the place had been hopping; with no fewer than two movie theaters, bookstores, drug stores and all of the other necessary components of urban life.

But by the time I reached high school pretty much all the commercial action had moved west, out beyond I-95, where an impressive new edifice called the Hollywood Mall had risen.

Downtown Hollywood had begun to dry up and blow away – just as Main Street commercial centers all over America were crumbling in the face of the inexorable march of commerce and people toward the ever-expanding suburbs in the Interstate Age.

So why not speed through downtown Hollywood, a young, stupid, hormone-besotted teen of the time (like myself) might have reasoned. All the better to get out of that Nowheresville on the double.

I only bring up this sordid incident from my past to make a few important points about drivers, downtowns and urban evolution.

To wit:

* If you give motorists the means and the motive to drive really, really fast, a lot of them do just that. Even if it’s in the middle of town. Hollywood Boulevard, with four broad lanes, provided the means. An all but deserted and seedy downtown provided the motive.

* If you turn downtown streets into thoroughfares so people can drive to the suburbs as quickly as possible, you shouldn’t be surprised if those downtowns begin to dry up and blow away.

* And these days, if you drive down through South Florida on I-95 and take a look at all the “suburban” malls that helped turn once-vibrant downtowns into urban dinosaurs, you may notice that a lot of them have themselves achieved dinosaur status – having succumbed in their turn to the relentless march of urban evolution. They can’t compete with the larger mega-malls that have sprung up far to the west of Florida’s “first” interstate.

All of which, I suppose, is a way of saying that time, drivers and progress are fairly ruthless predators in the relentless march of urban evolution.

Or, at least, they used to be.

Seems like old times

Recently, I had the opportunity to go back to Hollywood for the first time in many years. I was astounded to see that downtown Hollywood was booming – almost as though urban evolution had begun to march backward.

It has cafes, restaurants and jazz clubs. It has art galleries and dance studios. It has retail, offices and pricey over-the-store townhouses. An eight-story apartment complex with parking garage is rising just two streets away – the first new downtown housing in decades. A new downtown hotel recently opened its doors on Harrison Street, and the value of apartments in an aging high-rise on the other side of Hollywood Circle have shot up tremendously.

And downtown Hollywood is funky – with buildings painted in a variety of bright colors, and people wandering around in the wee hours of the night. At a sidewalk cafe, a woman in a red dress sang Italian love songs to the accompaniment of a keyboard and base guitar. People sitting on benches in a pocket park that wasn’t there before. All very cool.

“We’re like a mini-South Beach and a mini-mini Los Olas Blvd.,” says Louis Morningside, a jeweler who has done business in downtown Hollywood for 40 years, and who is delighted at its resurrection from near-comatose status.

So how did downtown Hollywood seemingly reverse the course of urban evolution and make that giant leap back into the future?

It put Hollywood Boulevard on a “road diet.”

It narrowed the downtown portion of the boulevard to two lanes of traffic, one going each way. It installed angle-in parking slots in the heavily landscaped center median strip to add to the parking that has always existed along the sidewalks. It slowed, not stopped, the movement of traffic through the heart of downtown.

It made downtown Hollywood safe once again for pedestrians, shoppers, entertainment-seekers and other living things.

And this on a major east-west corridor that handles nearly 21,000 vehicles a day – not all that different from University Avenue’s traffic flow.

So did the city trade a revitalized downtown for a gridlocked Hollywood Boulevard? I asked Hollywood Mayor Mara Giulianti if the narrowing of downtown caused traffic to back up to the west of downtown, toward City Hall.

“Yes,” she admitted. “On Friday night, because so many people want to come downtown.”

And listen, that gasoline-besotted teen driver in the ’54 Studebaker couldn’t have sped through the center of this downtown on a bet. It’s very design mitigates against speeding, reckless driving and other uncivil acts of motorized irresponsibility. It virtually forces motorists to be polite and act responsibly.

Something else, too: When the city narrowed downtown Hollywood Boulevard, it provided a convenient traffic detour by converting lanes on Harrison Street to one-way east, and lanes on Tyler Street to one-way west. But now the city is converting both those parallel “bypass” streets back to two-lane, two-way traffic because the detour route isn’t necessary.

That’s because Hollywood, like Gainesville, is built on a traditional grid system, and drivers who want to avoid the downtown “bottleneck” have plenty of options for doing so.

Oh yes, and these days, Harrison Street – once the “bypass” street – is getting almost as much activity and new business as downtown Hollywood Boulevard.

Downtown Hollywood, the scene of my boyhood, is back. So is “Main Street” Fort Pierce, Stuart, Delray Beach, Fort Lauderdale, West Palm Beach, DeLand, New Smyrna Beach and a few other once-moribund central city districts that I recently had occasion to pass through during a five-day, 1,000-mile tour of Florida cities that are on the mend.

Backlash on University

It was a tour I decided to undertake after the last Gainesville City Commission election that saw the defeat of one “new urbanist” incumbent and the “surprise” election of two Republicans who had campaigned against long-laid plans to reduce traffic lanes on University Avenue as a means of reviving that unattractive and economically stunted connector between downtown and the University of Florida.

For the winning candidates, the University Avenue issue turned out to be a “target of opportunity.”

“It wasn’t even an issue that was on my campaign platform,” said Commissioner Ed Braddy. “But I can tell you that from going door-to-door, this (narrowing University Avenue) is not something that was warmly received. People were 8-to-1 or 9-to-1 against it.”

The decision to redesign University Avenue from a four-lane thoroughfare to a three lane (one lane each way plus a turn lane) was made three years ago after an exhaustive series of charettes, workshops, public hearings and consultant studies. And it sits so far down on the area’s transportation improvement list that it won’t happen for several more years in any case.

If it ever happens.

Because, if the last election is any indication, public support for the project is weak to nonexistent. And given the results of the last election, it’s not even clear that redesigning University Avenue to make it Gainesville’s “signature street” could even get three votes on the City Commission anymore. Warren Nielsen seems to be the only unabashed cheerleader for the project left on the commission.

So is the University Avenue project one of those “smart growth” flights of fancy whose time has come and gone? Are we so jealous of our prerogative to drive 40 mph or faster smack through the center of town that we are willing to tolerate indefinitely the blight and economic stagnation of University Avenue as an ugly means to a necessary end?

I hope not. Because Florida’s premier university city deserves a better University Avenue than it’s got.

University Avenue really ought to be Gainesville’s showcase – a “destination,” not a thoroughfare. A place where people want to go to congregate, walk, park, dine, shop, work, live and be entertained. A corridor of urban culture that reflects the values of a town that brags about hosting Florida’s “flagship” university.

Anyone who has ever been to Madison, Wis., Boulder, Col., Berkley, Calif. or even Athens, Ga. – university cities with vital, attractive downtown centers that are worthy of the great institutions they host – has to be a little disheartened with our willingness to settle for something considerably less. And for what? The ability to drive quickly away from UF’s campus?

“I’ve been yelling and screaming for years, ‘let’s stop resting on our laurels and get a grip,’ ” says Linda Crider, an avid bicyclist with UF’s Department of Urban and Regional Planning. “We are way behind other university communities.”

Behind the curve

And it’s not just comparable university communities that make us look bad. We’re also “way behind” a lot of ostensibly less progressive Florida towns, as I learned on my recent five-day tour.

They say that travel is a broadening experience. But it can also be a bit depressing. Except for the beach, I remembered the Hollywood of my boyhood to be a somewhat unappealing city. Imagine my surprise to return home recently and find out that Hollywood proper has become considerably more attractive and economically vibrant than the enlightened university town I’ve lived in for more than a quarter of a century.

And if you really want to be depressed, visit DeLand, a college town less than half our size hosting private university, Stetson, that is nowhere near UF’s stature.

Woodland Boulevard, DeLand’s University Avenue, is one of Florida’s best-kept downtown secrets; winner of the “Great American Mainstreet Award” in 1997. It puts our little three-block downtown to shame. And if you picked DeLand’s downtown up and laid it down on top of University Avenue, it would easily stretch from UF’s campus to 6th Street – the section of University Avenue proposed for lane reduction.

“My parents live in DeLand, and I visit there a lot,” says Dotty Faibisy, who owns Wild Iris Books on University Avenue. “I can’t believe the number of people in downtown DeLand. Why can’t we be like that?”

Oh yes, and like University, Woodland, with its two-laned downtown “bottleneck” is a major traffic corridor through DeLand, handling nearly 20,000 vehicles a day. Volusia County recently built a brand new courthouse in downtown DeLand, and the town still hasn’t succumbed to “gridlock.”

“Why do they have a Main Street environment that is many times nicer than Gainesville’s?” asks Walter Kulash, the Orland-based traffic analyst who worked on Gainesville’s University Avenue study. “Why do they have cafes and bookshops and coffee shops and a wonderfully restored hotel and even aesthetically pleasing burger places in a market one-fifth the size of Gainesville on a street that is a major thoroughfare?

Good questions. But you might as well ask: Why Hollywood and not Gainesville? Why Delray and not Gainesville? Why Stuart and Fort Pierce and West Palm Beach and not Gainesville?

None of those cities are “exactly like” Gainesville. But all share our traffic problems to one degree or another (no one can seriously argue that traffic in Gainesville is worse than that in West Palm Beach, where they have made traffic calming a science), and all have managed to revive their core commercial areas despite their traffic problems.

The answer is depressing. Because we are willing to settle for less in Gainesville. Instead of a “signature” street that links our premier university with our isolated downtown, we are willing to live with a decaying urban thoroughfare engineered to interstate-highway standards for our motoring convenience.

So we can drive through that blighted strip as quickly as possible. And, honestly, it doesn’t look quite so bad when you’re driving fast. As Ed Braddy told his fellow commissioners the other evening, “I just drove here on University Avenue, and I thought the sidewalks looked fine. They looked plenty wide, and nobody was on them.”

Now there’s a big surprise.

“It’s very difficult to get anything done in a university town,” Ramon Trias, the Fort Pierce planning director who is recreating a Mediterranean village in the heart of one of Florida’s most unattractive cities, told me. “The people are all very bright, and they all love to argue about everything.”

To the extent that University Avenue is a reflection of Gainesville’s values, it reflects very badly indeed on our values. Because the truth is that while we all like to brag about Gainesville, it’s not a particularly attractive city in many respects. That’s especially true of our so-called “built environment,” our public spaces like University Avenue.

“I think to an extent, the problem is that we don’t really think of ourselves as an urban area,” says Ruth Steiner, professor of urban and regional planning at UF. “We tend to think of ourselves as a suburban community.”

Like South Florida

And here’s a nice bit of irony: For the quarter century I’ve been living in Gainesville, the most oft-heard rallying cry has been “We don’t want to be like South Florida.”

Well, guess what? A lot of folks in South Florida have decided that they don’t want to be like South Florida either, and they’re doing something about it.

They’ve started by taking back their old downtowns from the insidious auto-erotic culture that turned them into ghost towns in the first place.

“We’ve been sprawl-driven for 50 years, and while that may be nice for cars, it doesn’t do a lot for people,” said Tom Flemming, who was Main Street coordinator for Delray Beach when it underwent an astonishing downtown revival. “The wide, fast, straight roadway is the death-knell of urban life. You have to decide whether you want to be a through street or a destination street. If you choose to be a through street, you have to realize that you will always have a slum on either side of it, because that’s the best you can have.”

I wonder if we’re capable of learning from South Florida’s successes as well as its mistakes? My old hometown of Hollywood could teach us a thing or two about what it means to have a “signature” street that defines it’s community’s values and aspirations.

Not to mention how to keep fuel-injected teen-agers from using downtown as a drag strip.

 

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Designing Streets: Weighing Community and Mobility

By Pam Neary, Groundwork; (Summer 1998)

 

For over 60 years, America’s streets have been built at a scale that precludes pedestrian uses, undermines social interactions and denigrates the historic, cultural and aesthetic character of our communities. Streets are primarily designed to meet the needs of a mobile society and its businesses, encouraging the ever more rapid transport of people and products. But more and more neighborhoods have learned what works for transport doesn’t necessarily work for community.

Today’s oversized street standards became embedded in asphalt during the 1930s when the federal government took action to mitigate the economic effects of the Depression. In 1933, President Roosevelt established the Federal Housing Administration (FHA) to restructure the private home financing system with government mortgage insurance plans. By 1934 more than 70 percent of the nation’s commercial banks had federal mortgage insurance. In response to the popularity of the insurance, the FHA chose to protect their investments against risk by standardizing the type of housing subdivisions they would insure. To that end, they devised detailed technical regulations’ including road standards, for housing subdivisions. All federally insured projects were strongly encouraged to adopt these standards.

The FHA road standards were developed by the American Association of Highway Officials who, along with the federal government, asked the national Institute of Transportation Engineers to suggest traffic engineering guidelines and standards for safe, high-speed streets. First published in 1942, they recommended a 50-foot-wide right-of-way with 24 feet of pavement. Pavement width was widened to 26 feet of blacktop just a few years later. These standards became the guiding principles of road and highway design and were incorporated into FHA subdivision rules. By 1965, recommended road widths had increased to 32-34 feet of pavement and 60-foot rights-of-way. Over time, local governments have mechanically adopted these standards, primarily out of fear of liability.

Communities built to FHA specifications and designed to facilitate the been magnificently successful at discouraging the use of streets as public gathering spots. This has had measurable effects on the long-term viability of our communities. Those living next to highways or in neighborhoods amputated by high-traffic throughways know what happens when the outside environment is inhospitable: they endure declining home values and increasing noise, air pollution and neighborhood crime. In some communities, city officials have gone so far as to prohibit sidewalks. They have given the ravenous needs of commuters priority over those of their own residents who cannot or prefer not to drive.

Wider streets encourage higher speeds—but what about safety? Last year the City of Longmont, Colorado, partnered with Swift and Associates to examine this question. The study did indeed find a high correlation between road width and safety, but not in the direction the researchers expected. Narrow roads, they concluded, are safer than wide ones. As street width widens, accidents per mile increase exponentially. The safest streets were 24 feet wide and had an accident injury rate per mile about one-fourth the injury rate of the more common 36-foot-wide streets.

Armed with this type of into information and in response to ever louder complaints by residents, some communities are beginning to rebel. In “Governing” (October 1997), Alan Ehrenhalt pointed to a truckload of communities that have rejected the traffic engineers’ conventional wisdom. In the spring of 1997, Phoenix, Arizona, passed an ordinance to allow developers to use narrower streets in new developments, reducing road width minimums from 32 feet to 28 feet. Eugene, Oregon, went one better and reduced its standards for some roads to only 20 feet.

Other towns are reducing the size of already-existing roads. Instead of widening heavily traveled route through the center of town, Wellsley, Massachusetts, decided to widen the sidewalks and narrow the street. The University of Toronto worked with city planners to narrow a four-lane arterial into wider walkways with only two lanes for vehicles. Six lanes of U.S. Interstate 1 are being trimmed to two separate two-lane roads in West Palm Beach, Florida. In California, Riverside and San Bernadino now have two-lane principal downtown streets down from four lanes—and both cities are switching from parallel to diagonal parking to narrow the streets even further.

Vermont has decided to develop design standards that are more in keeping with the state’s local culture and the character of its small towns and villages. Targeted for change are arterial and collector roads, with reduced lane widths and shoulder widths. This year, Vermont legislators added a new narrative section to the old engineering standards that inserts respect for the local setting as an important design criterion. Some communities have even gone to the extreme of rejecting state and federal aid in order to set their own community-friendly standards. About two years ago both Guilford, Connecticut and Chester, Vermont, turned down large amounts of federal bridge building money (almost $1 million in Guilford’s case) because they opposed the feds’ requirements for big concrete bridges. Both did the job their way—and cheaper—with local money.

Rules from the past have saddled many American communities with overdesigned road systems that undermine the quality of life, but in other areas of the world community-friendly street design show high levels of residential satisfaction and stronger community interaction. Surveys in the Netherlands found that mothers and children consider their system of shared-use streets to be safer than ordinary streets. When living in neighborhoods with multiple-use streets Israelis exhibit increased communications between neighbors, and in Germany friendlier street designs have induced a 20 percent increase in children’s play activity. Changing the rules of the road is a critical first step in reclaiming community as a priority.

 

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Taking Back Main Street

Roads Less Taken

Cover story

January ’98 issue of Engineering News Record

——-

Across the U.S., highway designers and engineers aren’t just going “by the Green Book” anymore

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West Palm Beach, Fla., has a $1.5-million urban road reconstruction project in the works. South Orange, N.J., is spending almost $4 million on its major downtown artery. But don’t assume reconstruction means widening. In these cases, as in many others across the country, it’s just the opposite.

The same populace that wanted a massive Interstate highway system and still seeks federal funds for big new road and rail projects is rethinking the idea that bigger is better. There is a growing attitude among cities and towns across the country that roads should fit into the community, not the other way around. More municipalities are expecting transportation engineers and bureaucrats to work with their specific needs for livable communities where pedestrians–not automobiles–are the priority.

“The basic philosophy being looked at now is to generate more flexibility in highway design,” says Loren Evans, a retired engineer who chairs the American Society of Civil Engineers’ committee on local roads and streets. “There may be a bit of a design rebellion of a sort,” he says, although the ideas are “not shared by everyone.”

The rebellion has some vocal proponents, including architecture and planning critic Jane Holtz Kay in her book Asphalt Nation, published last year. Kay takes direct aim at A Policy on Geometric Design of Highways and Streets, the industry bible of highway design issued by the American Association of State Highway and Transportation Officials. It has “guided the slash and burn school of road straighteners for decades,” she writes.

AASHTO’s so-called “Green Book” describes recommended road widths, alignments and other features for optimal traffic safety. Few would dispute the idea that safety should be the first consideration inroad design. Even aashto officials such as Design Committee Chairman Thomas Warne, Utah’s transportation director, concede that it has been easy to take the principles for granted. “We haven’t been as flexible as we could be,” he says.

Recently, some states have begun to adopt new road design standards of their own, following the lead of Vermont, which did so last fall. Officials can use their own discretion in determining road and bridge length and width, and in setting speed limits–independent of Green Book recommendations.

Jeffrey Squires, deputy secretary of Vermont’s Agency Of Transportation, says other states have expressed “a great amount of interest in what we’ve done.” He emphasizes that the in-house rules are not changing Green Book standards. “We’ve tried to stress that solutions to highway problems are going to be unique and challenging and need to be approached in a creative way,” says Squires.”We’ve tried to

reconfigure the standards so that they give designers and engineers a great deal more freedom to come up with the most appropriate solution for the situation.”

Targeted areas are mostly arterial and collector roads where “we’ve reduced shoulder widths, lane widths and made some modifications to horizontal curb requirements,” says Squires. “We included a section that talks about context–a narrative section that encourages a designer to look at the project setting and come up with a design that fits within that setting.”

MAIN STREET

The point of it all is to preserve and enhance the quality of life and commercial vitality of U.S. towns

and cities, say proponents. A crucial factor is making more room for pedestrians and less for vehicles.

In South Orange, an old-line village of about 16,000 people in northern New Jersey, its main artery, South Orange Avenue, grew from a dirt road into a four-lane thoroughfare where too many cars whizzed past too few active storefronts. “There was a feeling that South Orange Avenue cut the village in half,” says Sal Renda, village engineer. To slow the flow, engineers expanded the sidewalks, created on-street parking spaces and carved center turning lanes that shrunk the roadway to one lane in each direction.

In West Palm Beach, five-lane Olive Avenue will become a two-lane road running through a residential

neighborhood.”Civic associations…came up with plans of their own and sold it to the city,”says Raymond Pippitt, Florida Dept. of Transportation project manager. They asked for landscaped traffic islands at each end of the road, “saying to the motorist, ‘You’re entering a neighborhood now,'” he says.

The idea of fitting a road–or bridge–into the aesthetics of the surrounding community has given rise to new opportunities in the private sector. Landscape architecture and road design often go hand-in-hand. Robert White is a Norwich, Vt.-based architect with highway access management training. His projects, which include scenic corridors, downtown street plans and strip development, have won federal Intermodal Surface Transportation Efficiency Act funding.

The RBA Group, a Morristown, N.J-based engineer, has built a practice in “traffic calming.” Traffic circles, narrower streets, curb extensions and textured crosswalks are all typical elements in this kind of street design.

Bettina Zimny, an RBA Group designer, says that municipal interest in traffic calming approaches has increased significantly in the past two years. “It’s a combination of streetscape elements and traffic engineers getting together and creating pleasant travel environments,” she says. No longer are streets built as “a wide expanse of asphalt that makes you feel like driving faster.”

Roundabouts, traffic circles and other traffic calming design methods are being used in places such as Eugene, Ore., where city planners are in the midst of a comprehensive review of street standards. City Engineer Les Lyle says they are considering how best to meld the needs of pedestrian bicyclists and mass transit with arterial roads. Eugene already allows streets to be as narrow as 20 ft, where once they had to be 28 ft as per Green Book standards.

SUPPLEMENTS

The Federal Highway Administration is soon to release a new document entitled Flexibility in Highway

Design that references “new urbanism” designs and specifically encourages consideration of historical,

community and aesthetic factors. “What it says is that designers have lots of tools to build flexibility into the process,” says James Byrnes, Connecticut Dept. of Transportation’s chief highway engineer and chairman of an aashto task force evaluating the new document.

Connecticut’s state legislature recently passed initiatives that allow bridges not part of the state highway system to be less than 28 ft wide and require consideration of community values and aesthetics in design. As for roads, “we’re not about building big wide roads any more,” adds Byrnes.”In this area of the country, clearly, the era of building new roads is over….There’s a sense of getting in values other than the standard of safety, although that’s still paramount.”

Connecticut’s municipalities are among those pioneering changes in how infrastructure coexists with rustic landscapes. The state movement has vocal spokes people, such as Alan Chapin, first selectman in the Town of Washington. “We’re lobbying for a set of rural standards from the state dot that would pertain to both bridge and road reconstruction,” he says. “Currently, small towns throughout the country are not eligible for lots of istea funding.”

Chapin hopes that as much as 5% of istea funds could be allocated to rural reconstruction. “I’m somewhat amazed that local road issues in this country have been ignored for the most part,” he says. “A lot of it is just plain common sense.”

Attention to low-volume and rural roads has recently gotten a bigger platform in asce. Documents obtained from a recent subcommittee meeting on the issue describe how designers must consider questions such as whether shoulders, guardrails and clear zones are needed on a road with a speed limit of 10 to 35 mph. The 10-ft clear zone called for in the Green Book might not be practical on a low-volume road, adding unnecessary construction cost, according to the documents.

CAUTION

Departing from Green Book standards might sound like a big liability risk, but Warne contends that neither the departure nor the risk are so drastic. “The Green Book allows virtually all the flexibility being asked for,” he says. “Communities are asking for the ability to take standards and adapt them. That exists within the framework.” If a design does deviate from Green Book standards, it’s up to engineers to document and rationally analyze the change as a safeguard against liability, he says.

“It’s a huge misconception that small towns aren’t willing to share liability,” says Chapin. “We’re asking [designers] to fix the road, but not by making it wider and straighter.” What needs to chance on the state and federal levels, according to Chapin, is “the concept of building roads bigger and wider so that years from now, if there’s a subdivision, we’ll be ready for it.”

Warne calls this a two-edged sword, citing examples of Utah towns that rejected bypass routes because they wanted the business the traffic would bring, but then changed gears as the congestion built up. “It’s an evolution of wanting certain things when you’re a certain size,” he says. “These are decisions you have to live with.” The key is cooperation between public and private sectors. “A road is not just a dot project,” says Carl Bard, Conndot principal engineer. “It’s everyone’s project.”

By Aileen Cho, with David Kohn, Debra Rubin and Steven Daniels, 1998 Engineering News Record

 

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Traffic Calming: An Overview

by Walter Kulash,

Glatting Jackson Kercher Anglin Lopez Rinehart, Inc.

Progress – July 1996

 

Traffic Calming: A Rapidly Growing Practice

Traffic calming devices are simple street design features that cause motorists to drive with more care, to drive more slowly or perhaps via another route.

The great majority of traffic calming devices make slight alterations to the street’s geometry, reducing its real or perceived width, or causing the driver to negotiate curvature or pavement texture. These modifications, almost always made within the public right-of-way, are usually accompanied by extensive landscaping, and serve as neighborhood landmarks as well as traffic calming devices.

Borrowing heavily from European and Australian experience, US cities have installed hundreds, possibly thousands of traffic calming devices over the past decade. Originally seen as devices to “retrofit” existing streets, traffic calming is now also seen as a part of original street design in new communities.

 

Why Calm Traffic?

Traffic calming measures are proposed in response to these widely-experienced problems:

Cut-Through Traffic-Cut through traffic has neither its origin nor its destination within the neighborhood, but rather is passing through the neighborhood on its local streets. Traffic engineers intend that through traffic use the major arterial streets, not neighborhood streets. This does not always happen, and cut-through trips seek out the local streets, sometimes because they are faster, and often because they are more pleasant and therefore seem to be faster.

Speeding-Many motorists (neighborhood residents as well as “cut throughs”) drive too fast on local streets. While some speeding is by irresponsible drivers, the majority is done by normally responsible drivers who find themselves “invited” to speed by the road’s design features, such as excessively wide pavement, straight sections of road and absence of vegetation. In addition to safety issues, speeding vehicles degrade the quality of the street for all other users, signaling that the street is extremely devoted

to traffic, imparting a general feeling that things are “not right” in the neighborhood.

Security – Excessive traffic speeds are a threat to neighborhood security, causing residents to retreat into their homes, essentially abandoning the street to vehicles and whoever else wants to claim it. Reducing traffic speeds and volumes through traffic calming measures are powerful ways for residents to start to reclaim their streets for their own needs.

Aesthetics-Wide expanses of pavement devoted solely to the moving of traffic have taken over much of our communities in the name of “traffic service.” Traffic calming provides the opportunity to use streets not only for moving cars but also as an aesthetically pleasing focal point for the community.

 

Menu of Traffic Calming Devices

Although there is a seemingly endless variety of traffic calming devices, they all derive from some combination of a few basic principles:

Narrowing the street reduces the speed that most drivers find reasonable and comfortable (the “design” speed). Narrowing is done through reducing the pavement width, adding parking to the street, or adding a median. At intersections, narrowing is complemented by tight corner radii. The perception of narrowing, which can be as effective as actual narrowing, is gained with street trees along the curb, overhead tree canopy, buildings brought close to the street and “gateways” along the street.

Deflecting the vehicle path causes the driver to slow and devote more attention to the task of driving. Deflection usually terminates long, straight (“tangent”) street views, thereby reducing their design speed. Deflection is done through curving the travel path of the automobile.

Sharing the pavement with other vehicles is a powerful way to slow traffic and raise the attention level of drivers. Long a feature of traditional local streets, shared-use can be re-introduced into other streets by selective short sections of narrow pavements, either at mid-block locations or near intersections. On-street parking can also compel shared use of the street.

Diverting the driver’s route makes vehicular access more difficult, and encourages the driver to use another route.

Diagonal street closures, one-way streets, median closings and turning movement restrictions are primary examples of diversion. Closing the entire street is EMPHATICALLY NOT an acceptable traffic calming solution.

Changing the pavement surface demands attention from drivers, and reduces the comfortable driving speed (the “design” speed).

Standard traffic control devices slow traffic through regulation. STOP signs, four-way STOP signs, turn-movement prohibitions, traffic signals and posted speed limits are the devices most frequently used to calm traffic.

Intensified enforcement of traffic regulations can calm traffic, generally by reminding drivers of posted speed limits and by enforcing the observance of STOP signs. Police officers are the usual source of intensified enforcement, but neighborhood volunteers can also provide effective work in this area.

 

Striking A New Balance

Traffic calming measures, while simple in concept, are a complete change in direction from conventional traffic planning of the past three decades. In conventional traffic planning, moving the most possible traffic at the highest affordable speed is the highest priority, and almost no neighborhood values are allowed to interfere. Traffic calming gives a new balance between traffic service and important neighborhood values, such as safety, walking and bicycling.

 

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Filed under New Urbanism: Timeless, Traditional, Walkable Design

Traditional Neighborhood Development: Will the Traffic Work?

Presentation by Walter Kulash at the 11th Annual Pedestrian Conference in Bellevue WA, October 1990.

 

Definition of Traditional Neighborhood Development (TND)

As participants in the Eleventh Annual Pedestrian Conference, this audience probably has a better feel for what TND means than any other group that could be assembled. Traditional neighborhood development, variously called “neotraditional” development or “urban villages” refers to a style of urban or suburban development, evolving since the 1970’s, that revisits many of the features of urban neighborhoods of 50 to 100 years ago.

If we had to give a single most distinguishing feature of TND, I would suggest that it is its continuous fabric of intimately blended land uses, arranged so that travel between them can be made by a variety of methods (walk, bicycle, transit, taxi) in addition to the usual privately-operated auto.

The land use in TND is mixed in an intimate blend, not, as in typical suburban development, in globules of single use parcels arranged in isolation from other uses.

The street design in TND is arranged to support this intimate blend of land uses. TND streets are small, and connected into dense networks. On these streets, there is an emphasis on non-motorized travel, and on the overall quality of travel for the automobile traveler. There is, at the same time, a de-emphasis of the narrowly defined performance standards (mainly travel capacity and speed) that are dictating what our streets and suburbs look like today.

The traffic engineering features of TND are attracting considerable attention and debate, because they seem to fly in the face of long-held principles of traffic engineering and subdivision planning:

Network of streets — the TND concept calls for a dense network of highly connected streets. In traffic terms, dense network means multiple available routes for a given trip. If the primary route for a trip is unacceptable because of traffic conditions, alternates are available. The dense network is in stark contrast to the sparse branched pattern of most suburban growth.

Street cross-section — the TND concept calls for street cross-sections that are typically no greater than two travel lanes plus on-street parking, which translates into a maximum pavement width of 40 feet. TND calls for a street right-of-way sufficient to contain this street cross-section, but not intended to

accommodate a wider pavement at later stages. Typically, a right-of-way width of 70 feet can accommodate the TND street.

Reduced or non-existent hierarchy of streets — the TND concept either eliminates or greatly reduces the ‘hierarchy’ of conventional functional classifications that are assigned to streets. In the conventional system, the base of the hierarchy is local streets, intended for immediate property access.

The next level is the collector, intended to gather traffic from local streets and feed it to the arterial system. The final level is the arterial street, intended for longer distance mobility and not intended to serve as immediate access to properties (although this function is almost inevitable).

Lateral clearance — TND guidelines permit and even encourages the reduction in lateral clearance between street and the fixed objects (trees, street furniture) on the side of the street.

On-street parking — on-street parallel parking is basic to TND. This parking is designed to buffer pedestrians on the sidewalk from moving vehicles in the traveled lanes to provide street activity (drivers entering and leaving their vehicles), for the supply of parking itself, although this source of supply serves only a small part of the overall parking need in a business district, and to “enclose” the sidewalk space.

Short traffic signal cycles — traffic signal lengths of no greater than 60 seconds are compatible with TND. Short traffic signals are pedestrian-friendly. They also create more frequent gaps in traffic for midblock pedestrian crossings.

Two-phase signals — these are signals that simply turn green for the entire approach, with no turn arrows. These are possible where there is a dense street network, because there is a much greater choice of locations for left-turn movements. The Conventional Suburban Development concept concentrates left-turn movements at a few major intersections, creating the need for multiphase signals. Two-phase signals convey a sense of small scale, to both drivers and pedestrians, that contrasts strongly to heavy-duty multiphase sequences. Two-phase operation permits a greatly reduced cycle time.

Curb radii — TND calls for a greatly reduced curb radii, typically 10 feet or less, at intersections to reduce the speed of turning automobiles and to greatly reduce the in-street walking distance required for pedestrians crossing the street.

Alleys – the TND concept frequently includes alleys serving the rear of all properties. These alleys eliminate the need for curb cuts for driveways in the streets, and permit continuity of buildings along a block front, Curb continuity further increases the amount of on-street parking that can be obtained in the design. Alleys are also intended to provide a utility corridor, thereby removing utilities, particularly power lines, from the streetscape.

Some other features, while not directly related to traffic, are highly characteristics of TNDs:

Architectural Themes — Most TND’s have vigorously pursued an architectural theme, generally following historical styles, further recreating the fueling of communities of 50- to 1 00-years old.

Many of these TND street features are old ideas revisited. TND proponents hold that these are ideas whose time has come around again, in a new and innovative way, analogous to the return of the four-cylinder engine or all-natural fabrics. Critics hold that these are just old worn-out ideas. The debate is getting interesting.

 

Will the Traffic Work?

Much of the criticism and suspicion that has been directed at the TND concept stems from a belief that the vehicular traffic will not work. it is frequently pointed out that many of the TND elements – narrow streets, small blocks, closely abutting buildings — are urban design features that were found to be incompatible with good vehicular traffic flow many years ago. The last 40 or 50 years of traffic engineering and land development regulation have indeed been directed at securing diametrically opposed features in our new development.

The debate about the traffic pros and cons of TND has been producing some interesting smoke and heat, but so far little light. Andres Duany, who with his partner, Elizabeth Plater-Zyberk are easily the most widely known proponents of TND, has, by way of traffic analysis, asserted that traffic engineers are in the lower academic half of their graduating engineering classes. At first, I thought that this was a compliment, implying that half of us in fact graduated. Presumably this contribution to the understanding of the traffic issues of TND was provoked by some comparably relevant criticism of TND on the part of traffic engineers.- The field of technical analysis of TND traffic is ripe for detailed traffic engineering analysis, and the results of precisely this type of analysis are what I will be addressing this afternoon.

In order to answer this question of whether or not the traffic works, let’s examine the three criteria that currently drive our traffic planning: vehicular capacity, travel speed (and therefore travel times) and safety.

How about other considerations, such as Pedestrians, or how the streets look? Remember, we said we are looking at the criteria used in traffic planning. Therefore, non-motorized travel and aesthetics can not, by any stretch of the imagination, be considered as serious driving forces in street design. To settle the question of whether the traffic works, we will focus on only those three ‘hard-nosed’ engineering measures.

 

TND has superior traffic capacity

A network of small interconnected streets has more traffic capacity than the same street area arranged in a sparse hierarchy of large streets.

This superior capacity is unrelated to the REDUCTION in travel demand or SHORTENING of travel distances that also results form the TND pattern. These decreases in total vehicular travel are also important advantage to TND, but we need to carefully isolate them in our analysis of TND traffic. The feature that we are focusing on is that for a given amount of traffic demand (i.e., same number of vehicular trips) the TND will simply out-perform the conventional street design.

 

Large Streets Have Deficiency of Scale

The fundamental reason why a dense network of small streets out-performs a sparse hierarchy of streets is that streets become less (not more) efficient as their size increases. So instead of an EFFICIENCY of scale as the street gets larger, we experience instead a DEFICIENCY of scale.

The reason is in the intersections. Intersections control the capacity of any network, dense or sparse. Think about it — if it weren’t for the intersections, every street would have essentially the capacity of a freeway lane, ideally 2,000 vehicles per hour (vph) and eroded, on surface streets, by various friction elements to 1,500 to 1,600 vph.

But unfortunately, surface streets have to share the intersections with other surface streets. So their capacity is immediately cut in half. Then the streets have to further share with left turns. If the streets are big enough, left turns are in all directions, left turns need their own piece of the intersection signal time, still only 60 minutes per hour, regardless of how big the intersection is.

Let’s take a somewhat abstract example of two different street patterns that illustrate this feature of traffic flow. In the first example, typical of the Conventional Suburban Development, we have a single large intersection of a four-lane divided and six-lane divided arterial street: each having left-turn lanes and protected left-turn signals. In other words, a well-engineered major intersection.

Let’s assume that this intersection is operating at close to peak-hour conditions, and that traffic service is beginning to be noticeably affected by the congestion. This corresponds to a level-of-service (LOS) ‘D’ at the intersection. This corresponds to traffic volumes of 3,000 vph on the six-lane street and 2,000 vph on the four-lane street, and turning movements of 300 and 200 vph, respectively, for the major left turn movements. The minor left turn movements are overshadowed, with respect to the signal time that they need by the major movements and are not significant in this analysis. The intersection described above is operating the limit of LOS ‘E.’ No further traffic can be added, in any of the major directions, without the LOS deteriorating to ‘F,’ or unacceptable.

Now let’s put the same amount of traffic on the same amount of pavement, but on a differently configured road system — a pair of two-lane streets intersecting three parallel two-lane streets.

In a corridor sense, that is, in the east-west and in the north-south direction, the total number of lanes remains the same as in the Conventional Suburban Development example. Also notice that the total amount of pavement stays the same. The radical difference between the two plans is in the number of intersections in each system — the TND has six times as many as the Conventional Suburban Development.

This large number of intersections reduces the turning movement load at any given intersection to a fraction (one-sixth in this example) of the turning movement load that exists in the Conventional Suburban Development pattern. Consequently, the entire system can carry greater traffic volumes at the same level of traffic service.

 

Turning Movements are More Efficient on Small Streets

The highly connected grid of streets that is built into the TND provides numerous, redundant opportunities to make a left turn. This contrasts to the pattern under Conventional Suburban Development, in which left turns are gathered up from multiple locations and focused at a single location.

Many, perhaps most of these left turns in a TND network can be accomplished in gaps, and do not represent the loss of any green time to opposing through traffic. Obviously, left turns can proceed simultaneously at different intersections, in effect multiplying the turn movement capacity of the entire network. On the other hand, when left turns are all gathered and focused at intersections, EVERY left turn represents a loss in green time to the opposing through traffic.

Not only does TND offer many more places to make turns, but it also decreases the difficulty of a given turning movement. It is far easier to make a left turn across a given volume of traffic in a single lane than across twice that same volume of traffic in two lanes, and so forth. So with multilane streets, you lose almost all of the capacity to make network left turns (street-to-street) and are left with only the ability to make turns into driveways.

This finding is another one of those unexpected conclusions, and is worth illustrating with an example.

When we make a left turn at an unsignalized location, we wait for an acceptable “gap” (around six seconds) to appear in the opposing traffic stream.

Even with a fairly normal heavy traffic flow, reflective of a peak-hour, with 900 vph, you will get a large number of acceptable gaps. The statistics say you will wait an average of 14 seconds until you receive an acceptable gap.

Now what happens as we simply double the traffic situation: twice the traffic and also twice the size of the road. Do we still have the same gaps? Do we still wait an average of 14 seconds?

We would if the cars came paired perfectly.

But, of course, they don’t come paired. And in fact, three things start to go wrong with the left turn movement: (1) the cars rearrange themselves, so that two-thirds of them are in the outside lane. We don’t need to know why, we just know they do it. So, some of our gaps are gone. Then, the additional traffic, of course, does not pair perfectly with the existing traffic. The second lane is, in fact, also a separate distribution of gaps, totally independent from the first lane. Only when we get occasionally lucky do the gaps coincide. Now the speeds are different, and cars start to change lanes and present the left turner with a more uncertain picture of what’s happening. Finally, the distance that we, as leftturners, have to clear has doubled, from one lane to two, and so we need a gap of not six seconds, but twice that or 12 seconds.

So all of these things working together mean not just a little more difficulty in making the turns, but a drastic drop in the ability to make them, to the point of impossibility. What is our solution?

In the Conventional Suburban Development, there is only one solution: move every last one of those turning movements to a signalized location, where, as we now know, they rob capacity

from all the other traffic movements.

 

Real-Time Route Decisions Occur on TND Networks

“Real-Time Route Decisions” is jargon for simply playing it by ear. In a TND environment, the driver can choose from the many routes available on the basis of what they see out on the street. In a TND, drivers make turns in advance or after their primary choice of turn location.

With the well-connected network in a TND, the driver can take alternative routes in the full confidence that the network is complete, and that they can find a reasonable route to their ultimate destination. Those of you that have lived in Phoenix with its highly connected network of streets know how this works. The importance of real-time decisions is that left turn movements stay out of the major intersections, and that minor streets pick up an important part of the turn movement load.

Real-time route selection is most likely to happen in peak-hours, when congestion is present.

This further explains the tendency of traffic volumes on local TND streets, to be more ‘peaked’ than traffic in general. Local streets are more likely to be pressed into service in peak-hours by drivers making work trips than in off-peak periods by drivers making mid-day trips.

 

Uninterrupted Traffic Flow is More Likely on TND

Uninterrupted flow conditions — meaning absence of traffic signals — are more likely to be obtained on TND systems than on sparse network. Freed from the sharing of right-of-way with other vehicles, the capacity of the street becomes essentially its free-flow capacity, ideally 2,000 vph and in reality, after considering side friction and other imperfections, around 1,500 to 1,600 vph.

Interrupted flow — as soon as a signal is installed — cuts the flow of the street to 800 to 900 vph, depending on the amount of time that is shared with the other movements at the intersection. So clearly, if we can stay beneath the threshold for signalization, we can preserve uninterrupted flow on streets.

At cross-streets, the need for signalization is reduced by greatly reducing the load on any given intersection, owing to a large number of intersections sharing the traffic load.

The fine-grained land use along the TND street also works toward the containment of the need for traffic signals. Small commercial properties, each with their own access, do not individually warrant signals, particularly in light of the relatively low main street volumes and the two-lane cross-section of the TND streets on which they front. Also, the probable commercial site on TND streets is small scale, and may in fact turn out to be junior versions of our currently familiar suburban community and regional shopping destinations.

 

What the Book Says About Capacity

The definitive method for measuring traffic performance, the 1985 Highway Capacity Manual developed by the Transportation Research Board and evolving from earlier methodologies over a 30-year period, is the definitive statement of traffic performance in the US.

The procedures within the 1985 HCM clearly confirm the basic premise of TND traffic flow; namely that there is no advantage of scale in large unconnected streets, and that a well-connected network of small streets will out-perform the sparse unconnected network of larger streets in terms of capacity.

For analyzing urban streets, the heart of the 1985 HCM methodology is the intersection analysis, since intersections, as we have seen, control the capacity of urban streets. in its planning method, (a short-cut approximation of the full HCM procedures) the 1985 HCM clearly states the diminishing returns on adding more traffic lanes.

Under the full detailed methodology, computationally complex, the deficiency of scale is not stated in simple rules, but is clearly visible when comparing capacity analysis results for identical traffic loadings applied to single, large intersections as opposed to a grid of smaller ones. The only way to really get at this, because of the inaccessibility of the method, is to run identical traffic volumes through different types of intersections and compare them. A series of several such comparisons shows the thrust; the grid of small intersections consistently out-performs a sparse hierarchy, for the same amount of traffic and under the strict application of 1985 HCM methodology.

In the view of many traffic engineers, the 1985 HCM method for unsignalized intersections is of marginal interest because unsignalized intersections are virtually designed out of conventional suburban design. However, the unsignalized intersection looms much larger in the analysis of TND, because of its ability to operate a large percentage of its intersections as unsignalized intersections. The unsignalized intersection methodology, more penetrable by manual analysis, very clearly shows the deficiency of scale of larger intersections.

These procedures, to put it simply, say that it is significantly more difficult for intersecting or turning traffic to cross a given volume of traffic in two lanes than to cross the same volume in a single lane of traffic. Consequently, the unsignalized intersection becomes less efficient as it gets larger.

 

What the Models Say About TND Street Capacity

We get the same conclusion about TNDs performance through the standard transportation modeling process. In one analysis, we took a development program that was proposed by one of our clients for a 700-acre site — a square mile. The development program was a typical planned unit development with single-family and multifamily homes, retail, and office park, schools and churches. We laid out this project in two different ways.

We then tested the traffic capacity of both the examples, using the standard transportation planning methodology. Some of you will know that this involves generating the trips, distributing them to their probable destinations and then assigning them to the street network that is in place. The computerized algorithm that does this — the model — simulates the decisions made by drivers in actual practice. Drivers take the best available route. When a route gets congested to the point that its speed degrades, drivers begin to divert to other routes, if available.

What we found in our prototype was that the TND was perfectly capable of carrying the traffic. The level of traffic service on the arterial streets actually improved in our prototype, because of the diversion to local streets. Collector street traffic virtually disappeared. Local street service, despite the shift of traffic to them, was virtually unchanged. The explanation lies in the ability of the large mileage of connected local streets in TND to absorb large amounts of traffic.

 

TND Has Lower Travel Speed But Comparable Travel Time to Conventional Suburban Development

TND has a shorter trip length than Conventional Suburban Development. This is due simply to the geometry of a dense network of streets, which minimizes the travel distance for any given pair of origins and destinations.

The shorter trip distances in TND are due to its layout. The TND pattern does not have any enclaves of development, and so therefore there is no element of enclave time — the time needed to drive into the enclave and drive out of it. In TND, a more direct routing is possible.

Another reason why TND trips are shorter is the absence of street hierarchy, with its need for routing all traffic onto a sparse network. Because the Conventional Suburban Development network is by definition sparse, it is therefore not direct, and forcing all traffic onto it creates the need for additional travel distances.

So far, we have been assuming an identical density of development, with both the TND and the Conventional Suburban Development developed to the same density. The argument for shorter trip distances under TND becomes even stronger when we project the increase in intensity that is intended as a part of the TND experience.

Under the TND, the interwoven mixture of trip destinations (shopping, personal business, employment, school) mixed in with the residential trip origins shortens the average trip length. Even without increasing the overall gross density, the TND land use pattern reduces the total trip distance for any given origin/destination pair.

This reduction in travel time illustrated by the analysis of the prototype TND and Conventional Suburban Development projects that we discussed earlier.

The travel speed profile for a TND generally shows a lower peak speed and shorter, more frequent intersection delays than on a Conventional Suburban Development.

The Conventional Suburban Development trip, made mainly on major arterial streets, is typified by a pattern of high speeds for short segments of road, interspersed with long traffic signal delays at individual traffic signals. The TND trip, on the other hand, with its greater use of minor arterial, collector and local streets, is characterized by low maximum speed, more frequent short delays at intersections and a greater number of turning movements.

For shorter trips, the TND pattern tends to produce lower trips times. This is largely due to the elimination of the large “threshold” of delay in getting out of the origin enclave and into the destination enclave for a typical Conventional Suburban Development trip. This threshold, usually involving entering and leaving a major arterial street at a long (120 to 180 seconds) traffic signal cycle, is eliminated in the TND pattern with its small accessible fronting streets and its interwoven land use pattern.

The travel time pattern illustrates a major and interesting features of the TND pattern of city design. The TND pattern gives good traffic service to the short trips (60 to 70 percent of household trips) that are made for daily needs. The TND is not as friendly as the Conventional Suburban Development to the long trips (30 percent of household trips) that are primarily for employment.

 

Quality of the Automobile Trip

The criteria of traffic capacity and speed measure only a limited aspect of the total travel experience. We submit that there are important factors, other than capacity and speed, that affect the quality of travel. At the present time, we don’t consider these measures when designing a road system, nor do we consider them in gauging the performance of the road system once in operation. From observation, however, we feel that these measures have a large bearing on the level of service that is actually experienced by the traveler.

 

The Traveler’s View is Awful

The typical arterial, designed for a 50-mile-per-hour (mph) design speed and carrying 40,000 to 50,000 vehicles daily (the “50/50 Arterial”) is a miserable driving experience. We should simply stipulate this as a basic premise. You don’t see these arterials in chamber of commerce brochures. You don’t see visitors coming here to Bellevue and asking to see strip commercial. Personally, I don’t like them, can’t find anyone who does, and think we can all agree that these things are simply a rotten environment for the drivers.

 

Why are they such a poor atmosphere?

*Pavement, everywhere. This is not exciting pavement. Not graceful, no beauty of form and function that we do see in some transportation works. This is ugly pavement.

*No people.

*No trees.

*Boring.

*Hot blazing in the sun in the sunbelt. Bleak anywhere else.

*Monumentally ugly traffic control de vices.

*Forest of overhead wires.

*Long, exasperating delays at traffic signals, with nothing in the blighted view to offset the waiting.

 

The 50/50 arterial, by its very nature, has an inherent drive toward ugliness; or perhaps certain ugly things are looking for 50/50 streets to settle on.

 

The Inevitable Sellscape

The packaging of 50,000 daily vehicles (and therefore, a total daily population of 60,000 to 70,000 drivers plus passengers) into a single arterial street leads inevitably to the irresistible urge to sell things to this population, and creates a sellscape along the street.

Containing this type of use of 50/50 streets is far beyond the will and ability of the typical local government. The 50/50 arterial is a gift-wrapped, gold-plated, gift to strip development. Once in place, almost no power on earth will stop its march toward strip commercial. Time spent berating local governments (counties and cities) for not doing better with these monstrosities (and I’ve done my share of this) is satisfying to the critic, but is unproductive. Once in place, it is too late to do much about the 50/50 arterial.

It is bad enough that we inevitably get a sellscape on our 50/50 roads. What is even worse is that get a miserable looking sellscape. Because of the inherent design feature of the road — the 50- to 60-mph design speed — we evolve a sellscape that is geared largely to the motorist passing by at 45 to 50 mph.

Visually, the sellscape is focused on a narrow cone, ranging several hundred feet from the driver. This full sellscape is enjoyed only by those drivers in the outer lane; things get worse as you get into the interior lanes. This 50-mph sellscape can be interesting and can entertain, particularly at first viewing. Some superior design and behavioral science talents have gone into making sure that this scene attracts your attention. The 50-mph sellscape is the highway equivalent of newspaper headlines: they catch your first attention, but don’t ‘impart anything more with closer inspection or repeated exposure.

At slower speeds, the driver’s field of vision broadens out to a wider angle. And what does the sellscape offer as you look at it more closely? Does the 50-mph feature now reveal a 20-mph texture, a finer grain, a deeper level of stimulation? No, it doesn’t. lt’s hollow, empty. It has nothing further to offer.

And at the stopped condition (where we spend a good portion of our travel time) how does the sellscape look? Even worse than at 20 mph, of course.

To follow the newspaper analogy, there are no bylines and no news story. No richness of information. No inverted narrative. If you’re not moving, the sellscape doesn’t want you, and can’t use you.

The street sellscape, like its television counterpart in the 30-second and 15-second commercials, has to go for the quick hard-sell. You do this by being strident, out-shouting the next seller, demanding attention or raising the decibels.

The individual land uses on the 50/50 strip may be attractive in other settings. The blight comes from how these are assembled into a 50/50 environment. For example, offices can have great driver eye appeal or zero appeal. Fast food restaurants that we like to criticize as auto-dominated can be part of the ordinary sellscape or contribute substantially to driver eye appeal. Commercial tourist attractions, a mainstay of our Florida growth, can also range from terrific driver eye appeal to absolute zero.

 

Boredom

The 50/50 strip may very well yield an interesting experience the first time or first few times you drive it. The message, however, wears thin and cannot stand up to repeated trips through it.

A typical work trip by a suburban resident, having only a single route available, will be forced through the same section of arterial 500 times annually. Many suburban residents are also hostage to the same strip of highway for daily shopping needs, thus raising their total exposure to given road segments to 1,000 or 1,500 times annually. The strip, with no depth of information or stimulation, is giving little more on the five-hundredth or one-thousandth trip than it did on the third or fourth trip.

 

Why is Auto Sellscape Any Worse Than Pedestrian Sellscape?

An interesting devil’s advocate question can be raised: Why are we being critical of the auto-oriented sellscape along the 50/50 arterial, and at the same time enthusiastic over the street-level pedestrian sellscape.

We value this greatly when we have it, we envy other countries for it, and as Andres Duany points out, we make tourist shrines out of the few places that achieve it. So why is it OK for pedestrians, but awful for motorists?

The answer, I believe, is depth of texture. A pedestrian-level sellscape, because of the low speeds of the passersby (and the ability to stop altogether) can offer a tremendous depth of possible interest. The pedestrian sellscape is interesting at the full pedestrian speed (four feet per second and 15-foot distance). This same sellscape, because of its richness of detail, can absorb your attention for large amounts of time at zero speed. There is a near-zero threshold of access to the greater detail: as a pedestrian, I can stop within seconds and delve into the deep layers of detail.

On the other hand, the sellscape on 50/50 arterial streets has no depth. It plays well (at least at first) at 45 mph; it doesn’t play at all at low or zero speed. Unlike the pedestrian sellscape, the threshold of access is huge. To get more detail, I not only have to leave the traffic stream, enter a parking lot and park, but also get out of my car and walk through a hostile parking lot environment.

We DO have interesting vehicle-oriented sellscapes — we just don’t seem to get them on the 50/50 arterials. Here, for example, is something from a vehicle oriented seascape that plays at 45 mph, at 25 mph and a distance of 50 feet, and even at the pedestrian scales of four feet per second and 15-foot distances.

The more we look at why we don’t have appealing vehicle-oriented sellscapes, the more we are led to the conclusion that we almost CAN’T have them at the 50/50 level; and that if we want more of them, we simply need to have less of our pavement in the form of 50/50 highways.

 

TND Yields a Superior Overall Trip Profile

One of the primary reasons for our current notion of arterial streets instead of a more livable pattern is that we have no criteria, in the planning and design process, that even measures livability in any way. Our dominating design criteria is basically one-dimensional: speed, or its related variable, capacity. Safety sometimes enters as a distant second.

Using this criteria alone, we will always select the solution that yields the greatest capacity, and therefore, the greatest travel speed.

What we have long felt intuitively, but are only starting to appreciate, is that our perception of travel is not one-dimensional at all, but rather considers a host of all kinds of other factors along with the ‘hard’ measures of time and speed. We could aggregate all of these qualitative factors into a single measure called “trip quality” an add this dimension to the strictly time measure and get a resulting profile of overall travel quality.

Now we are portraying not only the single dimension of time, but also a measure of the ‘goodness’ or ‘badness’ or the time as felt by the driver and passenger.

Using this time profiling notion, let’s examine two trips made for identical trip purposes: from home to the grocery store, located in the typical community shopping center.

In the conventional subdivision layout example, the trip begins at home, and first travels on a local street.

The trip then proceeds to a collector street, and from there to a typical arterial street.

At the destination, the traveler then moves onto what is essentially an internal collector within the shopping center.

The traveler parks and walks to the destination.

The first part of the trip, on the local street, is a pleasant, high-quality experience, as indicated graphically by the color (green) and the height of the color. However, after this initial segment of high quality, things begin to deteriorate. The next part of the trip, on the collector, is a boring, low-interest experience, due to the deliberate removal of all interaction from the roadside and replacing with a continuous wall. Things go from mediocre to bad as we reach the arterial street. Our introduction to the arterial street is a 70- to 90-second wait at a traffic signal, with nothing else to occupy our attention. Once on the arterial, we are exposed to the full dose of the 50/50 sellscape — the pavement, parking, lack of people. On our profile of travel quality, the level descends down into the deep red.

Things stay at that level as we enter our destination site — the shopping center parking lot. Our introduction to the site is along the ‘throat,’ essentially a piece of collector roadway whose purpose is to absorb clots of traffic from the arterial street, and let them make the transition from 45 mph travel to parking in a safe, off-street environment. It serves that purpose well. In overall quality terms, it rates more deep red.

At last, we come to the walk from parking space to store. Typically, this is a big negative. There are exceptions, certainly, but remember — we are talking about your typical community shopping center.

 

Typical TND Trip Profile

Now let’s make the same trip, between the same origin at home and the same destination at a grocery store, but this time on a TND network. As in the Conventional Suburban Development case, the trip begins with run on a local street. Because neighborhoods are linked with local streets (and not segregated into enclaved pods) the travel on local streets is likely to continue for several more blocks.

From the local street we move onto a collector, in this case a three-lane street with scattered commercial.

Following the design concept of TND, the collector street directly serves the shopping destination. Because of the smaller scale of the use, and the absence of the 50/50 arterial, the entire scale of the destination is reduced. As in the case of Conventional Suburban Development, we park in a lot and walk to the store.

The quality profile of this trip made on a TND network is radically different from the same trip made under Conventional Suburban Development conditions.

The TND trip sustains the high-quality throughout the entire vehicular travel, because it is made entirely on local and small collector streets. So instead of a continuously increasing mass of red, the TND trip maintains a consistent green, or high-quality profile. At the end of the trip, when we again find ourselves in the store parking lot, the quality of travel is, as in the case of the Conventional Suburban Development, negative. Standing on a big piece of asphalt is never going to come out green on this profile. However, even this negative aspect of the TND trip is less severe in the TND experience, compared to the Conventional Suburban Development. Because of the TND scale of development, the severity of the negative impact of the parking lot is less. Further, because it is smaller, we spend less time in it. So we reduce both the severity and the duration of our negative parking experience.

 

Comparison of TND and Conventional Suburban Development Profiles

A graphical comparison of the two profiles for our hypothetical trip show that they are radically different. Recall that when we applied only the one-dimensional measure of speed, the Conventional Suburban Development pattern yielded the shorter trip, and therefore was the higher-performing system.

However, when we add the dimension of travel quality we find that the quality aspect starts to outweigh and overwhelm the original time dimension, and the ” weighted average” experience of our entire trip quality Is very large under the TND model.

The net result of this type of quality difference is that the perceived time becomes significantly less for the TND trip.

For example, we could consider the time on local streets, because of their environment, to be perceived at 80 percent of clock time. Arterials, because of their offensive environment, have the opposite impact — a perceived time that is 30 percent greater than clock time. The time spent in the parking lot, the most offensive of all environments along our trip, is weighted at 120 to 150 percent of true clock time.

Working through the arithmetic points out what happens to the perceived (as opposed to the clock) trip times. Because it is largely on local streets, the TND trip computes out at only about three quarters of the time of the Conventional Suburban Development trip.

And even though this is just a contrived example, you can see that the results are what we engineers call robust. In other words, you will reach the same bottom line conclusion even if you vary the stipulated conditions considerably. For example, we could penalize the TND trip by making local street travel only slightly better than neutral, and by reducing the arterial penalty, and still retain the same conclusion of a lower overall perceived time for TND. What the example is telling us is that if we keep our local trips on local streets and downscaled collectors, we will overcome substantial differences in travel speed through the perceived quality of travel. The land use features of TND — smaller commercial sites interwoven into the urban fabric — will further reduce the terminal time for TND trips.

 

The Broken Profile

Another thought that these profiles suggests is that the continuity of a high quality travel experience may figure largely in our impression of our entire community. We may well have high-quality origins and destinations, but if every trip connecting them involves our being dragged out onto low-quality arterial streets, our overall impression of our community is marred. Even if you don’t see the blighted arterial streets from either your origin or destination, the realization that any travel is captive to them will spoil the concept of urban village that we are trying to foster.

The value of a continuously positive profile, or conversely, the damage done by a broken profile is one of those areas that we can only guess at now. We need more research here.

 

Overall Quality – A Long-Time Feature of Other Products

The notion of overall profile of quality determining its real value, while a novel, untested, unknown experience to us transportation planners, is old stuff to anyone who sells almost any kind of product. Take, for example, the product that runs in our networks — the cars.

As an engineer, I’ll tell you what that hard, measurable performance measures are: speed and capacity. So, do we try to sell cars by improving their measurable performance qualities? Absolutely not. Thirty years ago, the standard mainstream sedan had a capacity of six passengers, a top speed of 100 mph or so and a legally usable top speed of 60 to 65 mph.

Thirty years later, the standard mainstream vehicle has the same performance -six-passenger capacity and 100 mph, of which we can legally use 65 mph. In terms of the hard measurable performance, then, we haven’t improved t e cars at all. But have we improved the overall profile of the product? Immensely, through comfort, convenience and luxury.

With respect to automobiles, then, we have long ago “maxed out” the hard measurable performance measures of capacity and speed. Over the last 30 or 40 years, we have continued to improve the product, by adding to the nonmeasurable aspects.

You could repeat this pattern for almost any common product you can name. Yet, in the case of road travel, we are still trying, against increasingly difficult obstacles, to improve a single dimension of performance without paying attention to what really constitutes the quality of the experience in the user’s eye.

 

The Opportunity for Driver Interaction

In creating the sparse system of major arterials, we make driving an increasingly passive process for drivers. We create a situation in which drivers cannot, through their own efforts, improve their own driving experience — either the hard measurable features (speed) or their perceived quality — for a particular trip.

 

Limited Choice of Routes

The sparse hierarchy patterns of roads in conventional systems takes away any element of route choice for the driver. In the sparse network, there is only one route that can be taken. As a driver, I can’t match my route to my trip purpose — I can’t take a leisurely scenic drive home to unwind after work, I can’t impress an out-of-town visitor with a route that emphasizes the unique quality of my city.

Driving a sparse network will never develop skill from repetition. This is frustrating, and contrasts to our experience in other activities. In many of our other day-to-day activities, for example, grocery shopping or for many of us who still encounter a parking “problem,” there is considerable satisfaction with ‘learning the ropes’ and making satisfying decisions from the myriad of options available.

The ability to choose routes is important not only in improving the quality of the travel aspects, but is also a large factor in converting travel from single-purpose/ single-destination travel to a far more productive pattern of ‘linked’ trips, in which multiple trip purposes are served in a single series of connected trips.

When we consider the multitude of routes opened up by a dense network, and further consider the type of commercial response to dense networks, we can appreciate the potential for greatly changing the pattern of travel.

Nor, in the sparse hierarchy, do I get to exercise my skill, experience, judgment, powers of observation, or intuition to improve my travel time on my single available route. On the sparse hierarchy, in fact, I am limited to a meager choice of options for improving my performance: I can start my trip earlier or later. Further, I can cocoon myself off from the entire miserable experience by listening to an elaborate sound system or talking on my cellular phone. Or, through strenuous efforts, I can try to improve my travel speed and get the whole thing over with earlier. This approach, largely the province of young male drivers, involves competitiveness, hostility, aggression and a generally anti-social behavior. This type of driving is a large contributor to the “red” in the quality profile we saw earlier. This type of driving, despite its high visibility and the sheer quantity of unpleasantness dealt out to other drivers, produces interestingly small benefits to the practitioner, and none at all to traffic in the aggregate. For example, an extensive travel time survey in a southwest city found that for a three-mile trip, the difference in overall travel time between orderly driving in the traffic mainstream and highly aggressive driving was 17 seconds, or two percent of the total travel time.

Improving the individual driving time, furthermore, is not a systems benefit. Because traffic is a stream of incompressible vehicles, an aggressively driven vehicle imposes its advance in the flow only at the expense of the travel time of other vehicles — a win/lose situation and not a win/win situation.

Once the traffic volumes have neared saturation (70 percent or greater of capacity) aggressive driving takes the form of darting into any available gap (space) between vehicles ire adjacent lanes. The size of these gaps is set by the following drivers, and is their idea of safe following distance, based on speed, roadway condition and their own abilities. An aggressive driver darting into this space simply causes the following driver to slow down in order to restore the initial gap.

Even worse for traffic flow, this slowing, particularly if the driver brakes, may be followed by a “wave” of slowdowns extending backward (“upstream”) from-the point of the lane-change action.

Aggressive driving by a minority of the drivers does not improve the overall traffic flow and therefore the capacity of the road. Aggressive driving simply works the non-aggressive majority of drivers toward the back of the line.

 

TND and Non-Motorized Travel

TND is Friendly to Non-Motorized Travel

Since one of the driving motivations behind TND is to create pedestrian environments, it should come as no surprise to find out that in fact they perform well as pedestrian environments. It is worthwhile to consider the actual mechanics of why TND works so well, and to be able to defend the features that produce this friendliness to non-motorized travel.

 

Interwoven Urban Fabric Creates More Walkable Origin/Destination Pairs

Perhaps the single biggest underlying factor in the pedestrian-friendliness of the TND approach is the concept that land uses are interwoven in an intimate mix. This is something that, try as we might, we are simply not achieving in all of our so-called mixed-use developments. From a traffic point of view, even in the best of our mixed-use developments, we are afraid of putting origins and destinations together. It’s almost as though we have systematically worked to keep origins and destinations apart. It raises the interesting question of what market force is driving this separation.

It’s not within the scope of this traffic discussion to explain why our planned mixed uses don’t ever really mix, and our unplanned mixed use becomes delightful and transportation-efficient fabric. I feel that it has a lot to do with the size of ownership. If there are only large projects, there will never be a fabric. If there is a certain critical threshold of small, individually owned projects, then there will be the fabric.

Christopher Alexander, in his interesting book A New Theory of Urban Design, holds that the key to livable urban development is a mix of all sizes of projects.

 

More Origin/Destination Pairs Due to Intimate Mix

The intimate mix of origins and destinations in the TND concept places a large number of origins and destinations within walking or bicycling distance. It does this simply by breaking down the size of the origin only (residential) pods and the destination only (commercial) pods. This type of intimate mixing, even without any change in density, but simply by its geometry, brings large numbers of origins and destinations together.

 

TND Improves the Routes of Pedestrian and Bicycle Travel

More Direct Routing

TND, because of its intimate mix of activities and the density of network, provides a shorter travel distance for pedestrian trips. This is in most cases due simply to geometry. A dense network simply provides a shorter travel distance between any two points. The TND concept eliminates enclave pods of development, which typically have a 600- to 800-foot walking distance threshold, and a particularly ugly one at that.

The TND concept replaces this walking distance threshold with a greatly reduced threshold. The TND concept also removes the enclaves, and provides access in all directions to the site. So even in the absence of any land use changes, just the network in the TND brings many more origin/destination pairs into walking and bicycle distance.

 

A Better Bicycle and Pedestrian Environment

A series of small streets yields a better bicycle and pedestrian environment than a hierarchy of a few larger streets.

A given lane volume of traffic is more hostile to walkers/bikers on a multilane street than on a two-lane street that is the mainstay of the TND network. The reason for this deterioration in walk/bike environment is the enlarged intersection size on multilane intersections.

Specific problems with larger arterials are large-radius high-type traffic engineering features, shallow-angle crossings at ramps and turn-lanes, monstrous pavement expanses to be crossed, hostility of dual left turn-lanes to any type of human habitation, and general feeling, by walkers and cyclists, of being in an alien moonscape.

Just the sheer size of a single intersection exceeds the walking distance radius for even good environments, not to mention poor environments. Tortuously long traffic signals add further to these already improbable walk times.

Some other factors, not easy to measure, figure in the hostility of multilane roads to walk/bike travel. Competitive and aggressive driving is more prevalent on multilane arterials, because of the opportunity for drivers to improve their position at the expense of other drivers, with a corresponding loss of attention to walk/bike traffic. The sense of auto-domination at intersections of arterials has a profoundly discouraging impact on pedestrians. We all know the ingredients of this hostility. They are blighted streetscape, endless parkingscape, absence of any tree cover whatsoever, presence of overhead power.

 

Better Environment: Subjective Factors

A 20-mph environment along a TND street is vastly preferable for walk/bike travel to a 5O-mph environment along an arterial street. The 5O-mph corridor, even with high-type walk/bike facilities, is a poor environment because of the lack of interest.

What little visual interest there is in a 50-mph environment is lost when the speed drops to walking speed. What the walker/cyclist then notices at that the speed is the coarseness of roadside experience. In a TND environment, the visual texture of the dense fronting properties sustains a high interest, to the passerby, at speeds down to a slow walk. There are densities of one structure per 50 feet, and individualistic touches on all of the separate properties.

 

TND Multiplies the Number of Alternative Routes Available for Non-Motorized Travel

With the TND concept, there are an almost endless combination of alternative routes available for a given origin/destination pair. The walker/cyclist can select routes in response to real-time conditions (for example, a separate route for peak traffic periods versus weekend or midday travel). The multiplicity of routes available also lets the walker/cyclist match the route to their particular skills. For example, expert cyclists can choose to take their place in traffic as a fully-vested vehicle, while low-skill cyclists can travel on small, two volume, possibly more circuitous routes. All in all, TND presents a vast difference in opportunity over that which exists in the sparse hierarchical system, in which all walk/bike trips are forced up and down the street hierarchy.

The alternative routes can give large number of bicycle and walk trips a profile that totally excludes the use of arterial streets.

 

Roadblocks to TND

If TND is as attractive a development pattern as we have been arguing over the past few chapters, than why isn’t it the dominant form of new development?

We can offer some reasons, and we suggest that understanding these reasons can help advance the adoption of TND concepts.

 

Suburban Sociology – Throwing the Baby Out with the Bath

Conventional suburban street design first appeared in the wave of suburbanization that began in the late 1940’s after the close of World War 11. This first wave of suburbanization brought numerous benefits — first-time ownership of an affordable house, renewed availability of household appliances, resumption of automobile production. At the same time, the traditional neighborhoods, which the new suburbanites were leaving behind, became closely associated with undesirable features of the old life-style: burdensome family commitments, intrusive church presence, machine politics, single-bath homes, transit dependency, difficult parking for the new cars, and so on.

The association of the suburban community with everything “new” and desirable, and, conversely, the association of the traditional neighborhoods with everything “old” and undesirable has persisted for 40 years. The hierarchical street system and enclave project pattern became an inseparable part of the suburban ‘package.’ Along with the nice suburb you automatically got, as standard equipment, a nice unconnected street system.

The momentum for Conventional Suburban Development has persisted long after its original motivations have disappeared. The first cul-de-sac streets, for example, were intended for children to play in them safely, a reasonable idea 40 years ago with larger family sizes and no television. That design motivation for cul-de-sac streets, however, is long gone — children are fewer in numbers, and are all indoors watching TV instead 6-f playing in the street. Another example of an old design idea persisting: the employment pattern of 40 years ago, with strong downtowns and industrial concentrations, favored a hierarchical street system to carry the “many-to-one” traffic pattern that strong downtowns and industrial areas generated. That pattern has faded.

Similar to the people in the fable who accidentally discovered roast pig when their barn burned down, and then continued to make roast pig by burning barns down, we persist in trying to recreate the advantages of suburban living by reproducing a 40 year-old street design.

 

The Functional Class Myth

Traffic engineers, technicians by temperament and training, believe in things that can be measured. They like to sort, to find a structure, a harmony. This search for structure and order has evolved one of the fundamental ideas making our cities look the way they do. This concept is the functional classification hierarchy for streets.

This concept, now at the very foundation of all of traffic engineering thinking, has been around a long time and became standardized in the 1950s. Some versions of its origin say that it was meant to foster Civil Defense evacuation of cities during nuclear attack.

The functional class idea has an immediate plausibility — that at one end of the spectrum we should have streets that are meant for high speed long distance travel, carrying large volumes, and not hindered by local access. And at the other end of the spectrum, a local street, meant to feed other streets, carrying small volumes at low speeds. And in between, a collector street that does just what its name says — collects from local streets, maybe has fronting commercial uses like commercial, and feeds the arterial system.

Unfortunately, this hierarchy exists only in the minds of traffic engineers and planners. In reality, something entirely different happens. The idea that you can keep local access off the arterial streets is simply preposterous. I can tell you from our day-to-day work in development approval, that the 50,000 ADT arterial street is a gift wrapped, gold plated irresistible invitation to develop strip commercial. Think about it — we bundle together 50,000 vehicles with 60,000-70,000 occupants into a captive market. We make sure we don’t give them any other route. We ruin the roadscape, by the size of it, for anything else. And then we, in theory, expect strip commercial to stay off? Get serious.

It’s interesting to see what happens as the realization sinks in that that dense commercial activity access is not going to be kept off the arterials, but is in fact going to be attracted to it. The typical reaction, incredibly enough (but understandable in light of the emphasis on capacity) is to make the street bigger, now through frontage roads!

These are actually POLICY in some parts of the US such as California and as Texas. Fortunately, these are so excessive, in terms of cost, that they are not frequent and are not spreading fast.

In reality, a more believable model of access and mobility reads like an inverted curve, that says at very high volumes and at very low volumes access is the main feature of streets.

The concept of functional classification has parallels in all sorts of transportation systems. For example, we have 4 inch ‘local’ gravity feet sanitary sewer feeding to 8 inch collectors, then 12 inch force mains to central plants. Or power, where we have interurban 24,000 KV transmission, the ‘Interstates’ of the power grid, stepping down to 2,400 V transmission lines, to substations and to the 220 V local line into your house. These utility hierarchies are functionally classified in the strictest sense. For example, you will never see an individual home with “access’ directly onto a 24,000 KV transmission line.

There are also numerous examples of hierarchical structure in nature. For example, drainage basins start with creeks (locals) working their way up to rivers (arterials).

The body’s circulation system, which even furnishes the term ‘arterial’, its largest pipeline, to the largest size element of a traffic network, is a hierarchy.

Everywhere we look, in both nature and in man-made systems, we see hierarchical systems of flow. Why do these work so well everywhere else and work so poorly for traffic?

For one thing, all the other flows we gave as examples are focused at a single origin or a single destination — they are “one-to-many’ flows (e.g. electric power) or “many-to-one” flows (e.g., sanitary sewer). Traffic on the other hand, is a “many-to-many” flow, and is becoming ever more so.

More importantly, for all the examples we have mentioned, the measure of service is very simple — capacity and nothing else. There is no aspect of quality of experience for whatever is being transported in the system. To continue with the sanitary sewer example, the design of sewer systems properly does not consider any aesthetics as seen by the material being transported. In the case of highways, we unfortunately continue the same idea of service, and are paying no attention to the quality of the travel as experienced by the traveler.

Perhaps the most important distinction between traffic networks and all of the other flow networks both natural and man-made, that seem to be analogous is that of all of these systems, traffic alone involves human behavior. As we have noted, the presence of 70,000 persons daily passing along a road sets off strong, almost unstoppable series of development actions (“sell them something”) that greatly change the intended operation of the arterial street.

As traffic engineers working with private development, we see these actions on a daily basis. On the other hand, we don’t see the same drive to locate along 24,000 KV lines, or along a 12 inch force main.

 

No Constituency within Traffic Engineering Industry

We need to understand that the industry that we look to for moving people — the traffic engineering industry — has no constituency for doing so.

Let’s consider the range of possible goals of traffic engineering, as practiced on any level, local up to statewide, and see which one jumps out as the most likely.

The traffic engineering profession, which has perhaps the greatest influence of any group on how our new urban growth looks, is interested in one thing only — moving the maximum number of cars.

The profession is fixated on this goal. It does not see its charge as moving people in an attractive setting; it does not even see its goal as moving people.

Before we criticize this vision any further, we should understand that it is totally predictable, and is in fact simply a manifestation of a mature bureaucracy. We don’t even think about or question the fixation of other transportation modes on their own industries. For example, do we expect the airlines or their governmental regulators to recommend the development of rail corridors in air markets that are getting too dense for efficient air travel? Of course not. We expect the air industry to expand, build more airports, build more traffic control capacity — in other words, to just keep on expanding their own capacity.

What is useful to us is to understand that the only possible direction from change is outside the mainstream of traffic engineering.

 

Belief in Efficiency of Scale

The traffic engineering industry is based on an implicit assumption of efficiency of scale; that bigger roads are, like a bigger power plant or wastewater plant, more efficient. This is true for power and sewer. It is not the case for roads.

In fact, the OPPOSITE is true for roads. Rather than and EFFICIENCY of scale, roads have a DEFICIENCY of scale. We saw this earlier in the detailed analysis of capacity.

There is a counterpart feeling that administratively there is also an efficiency of scale, and that a large regional road agency will be much more beneficial than a myriad of smaller one. We are getting into something more subjective here, and there is no equivalent to 1985 Highway Capacity Manual to support the notion that agencies (like road capacity) are less effective with scale.

It certainly appears that the capacity for doing damage to communities through road design goes up with the size of agency. Further, road planning and building, a mature science, is fully within the capability of small sophisticated suburban jurisdictions with their professional staffs. Our host, City of Bellevue, Washington, with its population of 189,000, can plan, design and put to bid a given section of road for the same ultimate bid price as the State of Washington.

 

Holdovers from Strong Core Days

Much of our hierarchical street system concept is probably a holdover from the strong center days, when this kind of street system was indeed a valid response. I am going to spend zero time preaching to this choir that we are in a post-strong central city situation, and that we should think about retiring the hierarchical concept.

It is interesting that design of products and systems is LESS hierarchical. For example, the cellular phone breakthrough substituted an all-local grid for the sparse, strongly centralized hierarchy (two-way radio) that it replaced. Twenty years ago, all US automobiles were of the frame-and-body design, a hierarchical concept. Now 96 percent of all cars sold in the US are unitized body, in which the frame, and therefore, the hierarchy, disappears.

 

Conventional Suburban Development is a Great Cost Exporter

With conventional suburban design, much of the transportation cost of new development is shifted away from the private participants (the builder and the initial buyer) and shifted to the public at large. This ability to show a lower initial cost of new development is, needless to say, highly appreciated by builders and buyers, and they are quite happy to see the situation continued.

A typical enclave project in Conventional Suburban Development is, by definition, placing ALL of its external travel demands on the public street system outside the project.

The limitation of access to a single point, furthermore, increases the amount of travel distance that is needed to make any given trip. The pod itself is performing NO role whatsoever in carrying the systems traffic — it is all exported to the external, publicly built system.

The individual TND project, on the other hand, with its interconnected streets, carries a share of the regional traffic.

How successful are we at capturing the external cost from new development through impact fees and other assessments that are meant to exact the full cost of new development from that development itself? If we account for only the raw cost of building the new roads to serve Conventional Suburban Development, we can, as has been shown in Florida, quite readily pay for half or so of the cost of our current road patterns. However, in terms of degradation of environment, excess travel time and distance, and loss of opportunity for non-motorized travel, we can conclude that we are paying for enclave pods at the expense of degraded public realm.

 

Lack of Input from Other Relevant Fields

Despite its large influence on our daily life, the traffic engineering industry has a limited amount of input from other fields. As a result, we get street designs that very nicely meet the narrow engineering criteria that we adopt, only to find that, because of behavioral realities, they produce an unexpected and sometime totally contrary result.

We can best illustrate this kind of backfiring action by examples. Take protected left turns, for example.

These are supposed to make it easier to turn for the individual, and increase capacity. The actual impact, over time? Drivers are collectively forgetting how to make left turns at ordinary intersections, are clamoring for turn arrows everywhere, and system capacity is going down. A prime example on a citywide scale is Phoenix, which under public pressure had to finally install a large number of protected left turns, subsequently degrading the remarkable performance of its highly-connected street network.

Driver’s education is a classic example of a decision made without enough behavioral content. Everybody knows that driver’s education is a good thing, helps make more responsible drivers, and reduces accidents, right? Actually, just the opposite. The Insurance Institute for Highway Safety has concluded that drivers education INCREASES the number of accidents, and is on record in opposition to the inclusion of drivers education in schools.

One more recent example of what happens when only a single viewpoint tries to deal with a problem is just too good to pass up. A traffic engineering study, just recently reported in the ASCE Journal, was conducted in Huntsville, Alabama, to analyze the problem of vehicular collisions with roadside trees.

This analysis, done by traffic engineers, did a good job of data assembly and analysis, and identified an interesting profile of the typical driver involved in a collision with roadside trees. These accidents predominantly involve young male drivers, alcohol- or drug-impaired, in small group size, in early hours of the morning, in single-car accidents.

The profile was very conclusive, and suggests the following range of recommended remedies:

*Trees are doing a great job. Plant more trees.

*Get drugged drivers off road.

*Cut down trees.

Which of these three options do you think the traffic engineers recommended? You guessed it, “Cut the Trees Down”.

The list of similar apparently contradictory measures goes on and on. The common theme that emerges is that apparently sound traffic policies, when examined in light of all of their human behavior consequences, may in fact be counter productive. This concept is similar to the notion of counter-productive social programs that Edward Banfield presented so persuasively in his book “The Unheavenly City” several years ago.

 

Where Do We Go Now?

We have demonstrated, in the course of this discussion, that the traffic “works” in the TND pattern of land use. We feel strongly that further investigation into the technical traffic engineering features of TND will further deepen the support for its claimed circulation advantages.

We already knew intuitively that TND yields strong advantages for non-. motorized travel. We have shown, in this discussion, that the features of TND that promote non-motorized travel are complementary, and not necessarily hostile, to vehicular traffic circulation.

We all appreciate that there are large obstacles to the application of TND. This raises the question, then, of what are the feasible ‘do-able” measures that we can take to further enable the actual use of TND and related approaches to travel that seek to an alternative to the automobile-dominated design that we see in all our new growth?

The answer is that there is plenty of things that we can all do, starting right now.

Most of us here today are in the grouping referred to in the graphic as “Builder.” It goes without saying that developers and their designers and consultants fall in this category. Less obvious is the inclusion of many of you present at this conference — public works staff, city engineering and city and county administration — in the “Builder” category. This grouping is consistent, however, when we consider the point of contact with the development process – the entire group deals, on a daily basis, with decisions that immediately determine the built environment.

These daily decisions — for example, on street network configuration in new projects, on allowing enclave project, etc., will have an immediate impact on the shape of development. In the longer run, the “Builder” group is the logical focus of various ‘tactical’ actions, such as establishing the market feasibility for TND projects, and countering the misinformation surrounding the safety and liability aspects of unconventional street design. In the even longer run, we can raise the standing of TND and related design concepts to fully acceptable designs in the view of sanctioning bodies such as the institute of Transportation Engineering (ITE), and so forth.

The “Policy Maker” group, which applies to many of you present at this conference, are the logical candidates for the enormously important tactical task of getting TND language into local plans. This tactic, already meeting with success in numerous locations, is one of the most promising ways to advance the entire concept quickly.

“Personal Advocates” — individuals interested in the TND concept but not professionally involved in the planning/design/development fields, will most likely constitute a growing source of enthusiasm for TND as the public awareness of the concept continues to grow. We are certainly seeing this happen at the present time. The target activity for the “Personal Advocate” group is intervening in the local development review process (hearings, citizen review committees) and in seeking changes in local comprehensive development plans and land development codes.

 

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