Cars and Suburbs on Welfare

By Owen D. Gutreund

Twentieth-Century Sprawl (2004)


“The coordinated Good Roads movement had successfully lobbied government to provide better roads as a free-of-charge public good, ostensibly to get the farmer out of the mud. One of the most significant aspects of the landmark 1916 legislation was that there were no federally imposed user charges associated with the Federal-Aid highway program. Furthermore, motorists were protected from toll charges, and attempts to levy a federal gas tax had been repeatedly defeated by lobbying efforts of motorist groups, oil companies, and other highway lobbies…as a result, there was an enormous government subsidy of auto use, and the technical provisions of the Federal-Aid Highway Acts directed these subsidies exclusively toward rural areas. In effect, the federal government established a system of transfer payments, from urbanized regions to rural regions, and from all taxpayers to those who drove automobiles. In 1921, users of the 9 million motor vehicles in the nation paid only 12 percent of ALL highway costs.”

pp. 26-7.


“…the Hayden-Cartwright Act of 1934, which threatened to reduce aid to any states that increased ‘diversions’ of revenues from gas taxes to nonhighway purposes. The preamble of this act of Congress serves as an excellent example of the insertion of auto subsidies into the fabric of American political culture: ‘Since it is unfair and unjust to tax motor-vehicle transportation unless the proceeds of such taxation are applied to the construction, improvement, or maintenance of highways…’…many states passed legislation requiring that all gas-tax revenues be used to directly benefit motorists. Within a few years, 20 states had enacted CONSTITUTIONAL provisions to ‘protect’ highway revenues…As a result…gasoline consumption could not be taxed to support nonhighway expenditures, even though virtually no other type of consumption was similarly privileged. Highway construction was now sheltered…from the need to compete with education, law enforcement, prisons, or welfare programs for scarce government funds, unlike virtually all other government endeavors.”

“Entertainments may be taxed; public houses may be taxed; racehorses may be taxed…and the yield devoted to general revenue. But motorists are to be privileged for all time to have the whole yield of the tax on motors devoted to roads? Obviously, this is all nonsense…such contentions are absurd, and constitute an outrage upon the sovereignty of Parliament and on common sense.”

— Winston Churchill

pp. 32-5.


“…highway-related borrowing…was another powerful (albeit subtle) subsidy to automobility. Virtually all the highway debt of local governments…was backed by pledges of future revenues, mainly property taxes. Even at the state level, where user fees were levied, 20 percent of state road bonds were serviced by general revenues (in addition to the use of general revenues to fund road construction and maintenance). This meant that ALL taxpayers were bearing the burden of accommodating automobility, regardless of how much they used automobiles (if at all) or how much they benefited from lower transportation costs.”


pp. 36-7.

“The Interstate Highway legislation [1956] was the latest in a succession of laws that established and perpetuated a skewed American system of highway finance…the Act went a long way to closing any remaining gap between what was good for General Motors and what was good for the country….Over time, these measures established, then institutionalized, two related subsidy patterns. First, they undercharged motorists by a wide margin, penalizing the non-motoring majority while simultaneously inducing more and more Americans to adopt the automobile as the preferred mode of transport. In contrast, other developed nations in the world chose to impose user charges far in excess of road expenditures. A study of 14 industrialized European nations found that, on average, user fees were nearly three times the amount of direct highway costs, while in the US they were only about half. Second, American highway legislation consistently favored construction in unpopulated areas while impeding investments in urban transportation networks…The deductibility of mortgage interest was certainly a major component…[and] the sales tax on automobiles (which was invariably dedicated to state highway programs) was tax deductible. Likewise, employers could deduct the (often substantial) costs of providing free parking for workers, a benefit that was not taxable for the recipients. Company cars were similarly privileged. In contrast, any reimbursement for commuting by transit was fully taxable. More arcane tax provisions like the investment tax credit, and Accelerated Depreciation also favored corporate investments in new, unbuilt locations, instead of reinvesting at existing urban locations. As marginal tax rates rose during the postwar era, the power of these inducements grew, even as the Interstate Highway legislation sent automobility incentives to new highs…Cities and towns in all regions of the nation, of all shapes and sizes, were affected as resources were persistently directed to the periphery, away from downtowns and town centers.”

pp. 58-9.


“Concerned that Colorado was moving toward a user-fee funded system, the AAA and Good Roads groups obtained legislation…that imposed a statewide property tax for highway construction and a prohibition against locally levied user fees.”

pg. 68


“Americans who purchased cars could count on other Americans, even those who did not own cars, to share the cost of vehicle [parking] (in addition to the shared costs of usage built into the highway finance system).

pg. 81.


“As with many other motor vehicle programs, the general budget absorbed these [off-street parking] costs while benefits accrued only to commuting motorists, most of whom lived outside of Denver city limits.”

pg. 88.


[The new 35-year old mayor of Denver created the Denver Planning Office in 1949.] “Under [the new planning director], the…goal was clear and simple: ‘to give the automobile maximum freedom of direction and speed.’…Not only did the planners accept auto-dependency as an unalterable fact, they also embraced the notion that it was the government’s responsibility to meet the resulting demands without question, without alteration, and without charging motorists directly. As a result, their assumptions and forecasts became self-fulfilling prophesies…[The planning staff] offered a vision of new six-lane divided freeways with cloverleaf intersections (and a median strip too narrow to accommodate transit)…designated truck routes, re-timing certain traffic lights, and numerous street widening projects…even though the plan was geared toward the automobile, the planning office did not expect motorists to pay for it. This planning approach persisted for decades. A 1963 downtown plan focused almost entirely on increased automobility…the report dismissed [transit] because it was not self-supporting. Instead, it concluded that freeways ‘must be built’ to facilitate the flow of private automobiles…the report urged that access streets be widened and limited to one-way traffic, and called for $80 million of new off-street ‘parking terminals.’…a 1966 plan proclaimed that ‘the need for additional freeways within the urban area is acute and irrefutable when future traffic projections are examined.’…Despite its claim to comprehensiveness, the focus was exclusively on ‘street and highway systems and related highway-oriented transportation facilities for motor vehicles…[other forms of transportation] are not treated.’ It called for the expenditure of $200 million on freeways and $50 million on streets, with the city’s share of costs paid for by a bond issue that would be repaid out of property and sales tax collections…While the city’s planners indicated that suburbanization was inevitable, they in fact actively encouraged it. They planned to eliminate agricultural land use, increase low-density residential development, and limit high-density areas…[Denver planners] believed that ‘the mistake to avoid is over-concentration’ and ‘the advent of the private automobile liberated urban growth from central congestion.’ ”

pp. 89-93.


“…Middlebury’s [VT] entire share [of revenues for road and bridge expenditures] came from local property taxes, although the vast majority of the area residents did not yet own or drive a motor vehicle [in 1923].

pg. 140.


“…the lobbying group sought to maintain the growth of the automobility subsidy by removing what they called the “nonhighway” expenses from the highway department budget. In particular, they began to complain that money from the highway fund was used to pay for the state highway police. They argued that such costs would be more appropriately classified as law enforcement expenses and that motorists were being unfairly taxed, through gas taxes and registration fees, to pay for the highway patrol. This strategy…serves as an example of the relentless efforts on the part of the automobility lobbies to expand construction while keeping motorists’ contributions down to a small fraction of the total funds spent accommodating automobiles.”

pp. 156-7.


“The engineers in the state highway department considered the narrow portion along Court Street [downtown]…a nuisance for motorists passing through Middlebury [VT]…Many townspeople had a different perspective. For them, Court Street was a charming tree-lined and grass embanked approach to their small New England town. The engineers’ plan would have allowed four lanes of traffic along this congested stretch but at the cost of all the trees along the street…state policy required the town to pay half of the state’s share of the costs…Overrun by cars and sprawling in all directions, the town was being transformed, refashioned by the now-overwhelming influence of automobility, whether inhabitants liked it or not.”

pp. 183-5.


“Motorists have been persistently undercharged. This has produced more demand for automobility than supply. In response, [Vermont] has poured enormous sums of money into new construction (at the expense of maintenance), trying to help the supply catch up to the demand. The result is a highway system that the government can not afford to maintain and an economy that is now predicated on artificially cheap, subsidized automotive transport. Small towns like Middlebury, as much as big cities like Denver, have been remade by this dynamic, rapidly spreading out across the countryside…”

pg. 195.


“…the consistent underpricing of auto use produced an imbalance between supply and demand. Demand far exceeded supply for the economic commodity at hand: properly maintained toll-free and traffic-free roads. Public response to this disparity, under the influence of Good Roads movement rhetoric, was to build [wider] roads to satisfy the excess demand, without addressing the underlying disparity between the costs of automobility and the charges passed on to motorists. Furthermore, a consistent emphasis on new construction to help the supply of road-miles catch up to demand exacerbated the pricing problem, creating a highway system that governments could not afford to maintain.”


Erik Hare: Think Drivers Pay the Costs of Roads? It’s a Myth

Published September 7, 2003

Minneapolis/St Paul StarTribune


We tend to assume that driving pays entirely for itself, and that that’s reason enough for government to favor roads over other transportation choices. Not only do drivers pay for their cars, we believe, but also for gasoline that is taxed enough to cover the construction and maintenance of all the roads we’ll ever need.

But this is a myth.

Minnesota’s 20-cent gasoline tax would have to rise by 39 cents to cover all of the state’s current road-related expenses. To start building the roads we actually need in order to deal with congestion, the tax would have to rise 42 cents beyond that, pushing the price of gasoline beyond $2.60 a gallon.

Clearly, somebody besides the driver is paying for Minnesota’s roads. Drivers-through gasoline taxes, car registration fees and sales taxes on vehicles-actually pay only 62 percent of the costs of roads. General taxpayers “subsidize” the rest, no matter how much or little they drive.

Because of this arrangement, a good portion of Minnesota’s demand for roads is forced to compete with the whole array of other pressing government needs. This competition now threatens the integrity of our road system, especially in busy urban areas. It also chokes off opportunities to provide other viable transportation choices, like transit.

The problem’s roots date back to Model T days. Dirt roads were fine for horses, but muddy roads were terrible for cars. The political cry to “Get the farmers out of the mud!” led to changing the state Constitution in 1920. A system of paved trunk highways, plus help for county and city roads, was to be funded by a gasoline tax and a vehicle registration fee. Thus pavement replaced dirt.

Much has changed in 83 years, but the outline of that financing structure remains in place. A formula for the distribution of state gasoline tax revenues (62 percent to the state, 29 percent to counties and 9 percent to cities) took effect in 1956, but that hasn’t changed either, even as the state has become considerably more urban and our economy more diverse and sophisticated. We still have a transportation financing scheme designed mostly to get farmers out of the mud.

Thanks to this antiquated system, Minnesotans who tend to drive the least-urban residents-tend to pay a disproportionate cost for roads. Not only is this unfair; a heavy reliance on property taxes leaves the entire road system vulnerable to other budget constraints.

St. Paul offers a good case study. Public Works is the largest department in city government, accounting for more than a third of municipal operating costs. It spends most of its money on roads-$67.3 million last year.

But only about 30 percent of that comes from driver-generated income on parking, snow-plowing fees and so on. The other 70 percent comes from general revenues, assessments based on street frontage and type of property, and an infusion of $10.3 million from the city’s general fund-money that must compete with police and fire operations and other pressing needs.

That’s still not the whole picture. Debt service is a major part of city spending. This year, 36 percent of St. Paul’s $78 million in bond repayment will go to cover road projects. That’s an additional $19.9 million draw on the city’s hard-pressed general fund.

The bottom line is this: Only 24 percent of the cost of St. Paul’s roads is borne by driver-generated taxes and fees. The other 76 percent is a subsidy from general revenues and property assessments. There’s no reason to believe that St. Paul’s situation is atypical for cities and older suburbs.

This scenario is repeated in developing suburbs as well, where state-aid roads are only a part of the picture. Feeder streets that are not part of the antique aid system are also funded by local property taxes, and these costs have to compete with other brand-new infrastructure that has to be built daily.

This pressure is worsened by the state’s reluctance to keep up with transportation needs. The Transportation Policy Institute recently estimated Minnesota’s unmet needs at $1.2 billion a year to prevent further congestion, bridge closures and so on. The current rate of spending doesn’t even begin to meet our needs, says Anne Finn of the League of Minnesota Cities.

“We’re just not planning for the long-term viability of our paved streets,” said Don Sobania of the St. Paul Public Works Department. “My crystal ball doesn’t show me where that money will come from.” A lot of the blame for this situation belongs to a funding system that does not direct money to where more of it is spent-the cities.

We’ve been less than honest with ourselves about how transportation is paid for in Minnesota. We’ve heard a lot of misleading rhetoric in recent years about cars and roads being the superior choice because they are entirely paid for by users, while transit is heavily subsidized. But if you add up all the money spent in Minnesota on transportation, then subtract the money contributed directly by users-at the gas pump, through registration fees, through sales taxes on new vehicles or at the transit fare box-you’ll find a leftover subsidy of $1.3 billion from general taxpayers. Of that total, 89 percent went to roads.

Our transportation financing system is as outdated as the Model T it was meant to accommodate. Relying on a patchwork of local property taxes to shore up the road system obscures Minnesota’s real transportation picture and crowds out the funding of transit and other alternate modes. It’s time to stop pretending that driver-related taxes and fees pay the entire cost of building and maintaining our roads.


Erik Hare is a research engineer living in St. Paul.


Excerpts from the book “Home From Nowhere”

by James Howard Kunstler


Everything we love and care about in this world is subject to the tragedy of eventually being lost to us, including our very selves. The easy response to this terrible condition is to create a world of things that are not worth caring about. That is precisely what we have done in the United States. That is why the suburban housing subdivisions are so sickening in their banal, endless replication. They deny and confute the tragic nature of life because they are places not worth caring about. … In the heartland, mobile home parks are commonly referred to as “tornado bait.” Nobody could say that about an Italian hill town and get a laugh, not even an American.


The problems of the cities are not going to be relieved unless the middle class and the wealthy return to live there. For the moment, these classes are off in suburbia, inhabiting those “little cabins in the woods” grouped together in the subdivisions as a symbolic antidote to the city. They will not return to the cities unless a couple of conditions obtain. One is the economic failure of the suburban equation, a likely event. A second condition is whether the cities themselves can be made habitable.


Anyone who travels back and forth across the Atlantic has to be impressed with the difference between European cities and ours, which make it appear as though World War Two actually took place in Detroit and Washington rather than Berlin and Rotterdam.


Notice that there are no magazines in America called Neighborhood Living, or Towns Beautiful. What would we show? The supermarket parking lots of Beverly Hills are just as depressing as those in any lumpenprole subdivision town outside Scranton, Pennsylvania.


While I believe we have entered a kind of slow-motion cultural meltdown due largely to our living habits, many ordinary Americans wouldn’t agree. They don’t perceive a crisis. … Economic forces are underway that will require us to live differently. The only question in my mind is whether the fabric of society will be torn apart in the process.


We have the knowledge to do the right thing; we lack only the will to do the right thing. The inescapable conclusion is that our behavior is wicked, and that we are liable to pay a heavy price for our wickedness by losing things we love, including our beautiful country and our democratic republic.



Associated Press Writer

NEW YORK (AP) — Three years after he published “The Geography of Nowhere,” a bitter screed against modern American planning and urban design, James Howard Kunstler is back with advice on how to get “Home From Nowhere.” Kunstler’s latest book, in stores this month, continues his crusade against America’s automobile-dependent “suburban crudscapes” of “one … office park after another, pod-upon-pod of income-targeted houseburgers, strip after numbing strip of chain stores, fry pits and multiplexes.”

The suburbs that have blanketed the United States in the decades since World War II not only are irredeemably ugly, Kunstler argues, but have shredded the fabric of American life and are slowly bankrupting the nation.

“We’ve been engaged in a process for two generations of degrading the public realm of our towns and our cities and our neighborhoods,” Kunstler said in a recent interview. “The damage now is so tremendous that there’s really some doubt we can continue to be a civilized society.”

A Manhattan native, the 47-year-old Kunstler now lives in Saratoga Springs, where he writes novels and nonfiction.

Kunstler said he has followed planning and urban design issues since he first worked as a reporter in Albany in the early 1970s. After leaving journalism for 10 years to write novels, he returned in the late 1980s, focusing primarily on land use. “The Geography of Nowhere” emerged from that work.

Kunstler blames America’s decline and sprawl on the nation’s slavish devotion to the automobile and a planning establishment that designed an expensive national infrastructure around the car.

The average new car now costs $20,000 and about $6,100 a year to keep on the road. But those sums don’t begin to cover the massive indirect costs of an auto-based culture, Kunstler says.

He estimates the costs of driving that motorists and truckers don’t bear directly — road construction and maintenance, car accidents, air and noise pollution, productivity lost in traffic — at about $300 billion per year. Most of that, he says, “is fobbed off in the form of government debt onto generations as yet unlicensed to drive.”

Few realize that the trashy and alienating environment that resulted from the nation’s post-World War II migration to the suburbs is to blame for many of the country’s current social and economic woes, Kunstler said.

“The civic life lost in this process could not be reconstituted in the suburbs, because proximity was made illegal” by zoning laws that mandated large lots, acres of parking and wide, car-friendly streets, he writes.

But he sees hope.

“Ordinary Americans are beginning to make connections between these things,” he said. “They’re beginning to realize, `Oh, there’s a connection between the fact that I’m spending two hours a day being the family chauffeur and the fact that my kid is painting his head purple.’ ”

Though the link between driving the kids to soccer practice and adolescent alienation may seem tenuous, Kunstler’s impassioned prose and his explanation of suburbia’s historical context show that this quintessentially “normal” American way of life is in fact quite abnormal.

In “Home From Nowhere,” Kunstler advocates a return to traditional modes of city and town planning that has been labeled the “New Urbanism.” And he casts his eye about America, critiquing cities’ attempts to remake themselves.

Providence, R.I., wins praise for its efforts to attract artists and young people to live in abandoned office buildings in its downtown district. Cleveland gets a raspberry for dropping a mindless suburban strip mall into a depressed neighborhood and touting it as urban redevelopment — “a recipe for a new Dark Age,” Kunstler writes.

He also re-evaluates his hometown of Manhattan, 30 years after he fled for college in upstate New York. “For all its present difficulties,” he writes, “I believe New York will endure even when other American cities like Los Angeles and Phoenix implode, because New York’s physical armature is so sturdy, and because it depends so little on cars.”

The compact, neighborhood-centered development found in much of New York is the solution to our suburbia-induced woes, according to Kunstler, who argues that zoning laws should be changed to help develop half-mile-square, pedestrian-friendly neighborhoods accessible by public transit.

Such design would revive the small town Main Street of yesteryear and replicate features that have made urban neighborhoods like Washington’s Georgetown, Boston’s Beacon Hill, San Francisco’s Pacific Heights and New York’s Greenwich Village some of the nation’s most desirable places to live, Kunstler


Without such radical changes, the nation is headed for economic and social disaster as oil reserves dwindle and the suburban lifestyle becomes increasingly untenable, Kunstler predicted.

“Extreme automobile dependency is at the bottom of a lot of economic problems for Americans,” he said. “We are going to create a grievance-laden class of people who are going to express themselves politically in an irrational way, like by electing people who make Pat Buchanan look like St. Francis of Asissi.”

Though he sees a solution in the New Urbanism, Kunstler said it may be too late. He draws parallels between America today and Weimar Germany in the years before economic instability and social insecurity allowed the Nazis to come to power.

“There’s not necessarily a happy ending to this,” he said.


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.


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


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.”


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.


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.


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


Brave New World

by Melissa Herron, Builder Magazine, July 1998


Excerpted quotes

City buyers aren’t motivated by the factors that lead people to buy in far-flung suburban locations. “People who move downtown want vibrancy…They are there strictly for the lifestyle.” –Dan McLean, veteran Chicago infill builder.

…suburbs just aren’t the utopia they used to be…”People once moved to the ‘burbs to escape crime and congestion and traffic jams of the city. But now the suburbs have all that.” –Andrew Warner, sales and marketing director for a high-rise condo builder in Chicago.

“People are coming back to the city because they’re tired of the sterile feel of suburbia.” [Bernie Glieberman, president of Crosswinds Communities in Detroit] Yet suburbia is exactly where most builders have built for the past four decades. [M. Herron]

70 percent of those surveyed preferred the concepts of New Urbanism — pedestrian orientation, community gathering places, and close-by shopping — as long as they could have privacy.

30 percent of those surveyed said they preferred an urban model where they could walk to conveniences. [M. Herron] “This is in a place that has no model, no basis of comparison to suburbia…I would say that means probably close to half the market wants it,” says Chris Lineberger, vice president of market analysts Robert Charles Lesser & Co.

“A substantial portion of buyers don’t want to live in the suburbs.” –Glen Barnard, president of builder Kaufman and Broad’s Denver division.

The neighborhoods that more and more consumers are scouting these days are close in. The beauty of infill locations is that the amenities are in place, and they have character. There’s no waiting for chain grocery stores and franchise restaurants, as is often the case in suburban settings. Shops, schools, and cafes already exist, along with theatres, libraries, art museums — you name it.

What attracts the older crowd? “Food, restaurants, nightlife, restaurants, restaurants, and food.” — Roger Mankedick, sales and marketing vice president for Concord Homes in Chicago.

75 percent of households don’t have children under age 18, making them prime candidates for urban infill projects.

Questions about crime often disappear after enough buyers move in, according to McLean. “People watch out for each other. Density creates safety.”


The Second Coming of the American Small Town

By Andres Duany and Elizabeth Plater-Zyberk

Wilson Quarterly, Winter 1992


[The following essay is the foundation for the famous, circa 1992, presentation made by Andres Duany in Boston, entitled “The Merits of Neo-Traditionalism,” which is widely considered to be the speech that started the internationally prominent New Urbanism movement.]

Three years ago, Dade County, Florida sentenced itself to the absurd fate of perpetual Urban adolescence. Responding to a state mandate, the county government adopted a package of “balanced growth” measures, conceding that traffic congestion and growing demands on the public purse for roads and other infrastructure had made it impossible for the city of Miami to grow any further in the old way. Most citizens were pleased. The reaction against growth has become a national phenomenon, although elsewhere it is often much less organized and much more emotional. In California, that harbinger of everything to come in this country, it has reached near-suicidal proportions. In Santa Cruz County, restrictions on growth have crimped the tax base: Three bridges have been closed for lack of funds to pay for repairs. But the people of Santa Cruz apparently would rather endure such difficulties than grow.

This is unprecedented. Never before in American history has growth been so unwelcome. After all, growth signifies more people, more commerce, more prosperity, more culture. It is in the nature of cities and towns to grow, and when they grow no further, like all organisms, they begin to die. What is responsible for this bizarre antipathy is not growth itself but the particular kind of growth we have in the United States. Suburban sprawl is cancerous growth rather than healthy growth, and it is destroying our civic life.

Americans are only beginning to understand that this is so. Many Californians are no longer interested in building more highways to make traffic flow more smoothly; not unreasonably, they now simply want less traffic. The credit for this change belongs partly to the environmental movement, which has persuaded most Americans of the need to stop ravaging the landscape and polluting the atmosphere with ever more roads and cars. But Americans are also beginning to recognize an important fact. It is not only the atmosphere or the animal habitat that is endangered on this continent. The human habitat is threatened as well.

Growth gone awry can be seen anywhere in suburbia but nowhere more clearly than in the “planned communities,” based on derivative versions of the planning ideals embodied in Reston, Virginia, or Irvine, California, that have proliferated on the suburban fringes since the 1960s. Examined piece by piece, these planned communities do seem to of many of the things that Americans say they want: convenient workplaces, well-managed shopping centers, and spacious, air-conditioned houses full of the latest appliances. But why, when they get all of this, do Americans hate it so much that they want to stop more of it from being created?

“No more of this!” they say. “It is ugly and it increases traffic.” They are happy with the private realm they have won for themselves, but desperately anxious about the public realm around them. Because of the radical malfunctioning of the growth mechanism, the late 20th-century suburbanite’s chief ideology is not conservatism or liberalism but NIMBYism: Not In My Back Yard.

Suburbanites sense what is wrong with the places they inhabit. Traffic, commuting time, and the great distances from shopping, work, and entertainment all rank high among their complaints. But all such inconveniences might be more bearable were suburbs not so largely devoid of most signs of “community.” The classic suburb is less a community than an agglomeration of houses, shops, and offices connected to one another by cars, not by the fabric of human life. The only public space is the shopping mall, which in reality is only quasi-public, given over almost entirely to commercial ends. The structure of the suburb tends to confine people to their houses and cars; it discourages strolling, walking, mingling with neighbors. The suburb is the last word in privatization, perhaps even its lethal consummation, and it spells the end of authentic civic life.

Is there an alternative? There is, and it is close at hand: the traditional American town. This is not a radical idea-far from it. When the Gallup Organization asked Americans in 1989 [what kind of place they wanted to live in, the most popular choice was] a small town. Only 24 percent chose a suburb, 22 percent a farm, and 19 percent a city. One hardly needs an opinion to discover the allure of towns. The market reveals it. Americans have shown over and over again that they will pay premium prices to live in the relatively few traditional towns that remain, places such as Marblehead, Massachusetts, Princeton, New Jersey, and Oak Park, Illinois.

All of the elements of towns already exist in the modem American suburb. For various historical reasons, though, they have been improperly assembled, artificially separated into “pods” strung along “collector roads” intended to speed the flow of traffic. The pods are specialized: There are housing “clusters,” office “parks,” and shopping “centers.” These elements are the makings of a great cuisine, but they have never been properly combined. It is as if we were expected to eat, rather than a completed omelet, first the eggs, then the cheese, and then the green peppers. The omelet has not been allowed to become the sum of its parts.

The tragedy is that we could have been building towns during the 1970s and ’80s. But all of that wonderful growth has been wasted, and it is doubtful that we will ever see anything like it again in our lifetimes. Misguided planning, not rapacious real-estate developers, is chiefly to blame for this gross miscarriage of growth. Left to their own devices, developers would have every incentive to build towns. Because towns are more compact than sprawl, the cost of land, streets, water and sewer lines, and other infrastructure is lower. And they can be built at lower risk, in small increments.

The town is a model of development well-suited to times of economic adversity, and it dominated American thinking until World War II. But postwar developers were guided by a new model that emerged out of government economic policy and planning legislation. Matters were complicated by the fact that each of the elements of the town emigrated to the suburbs at different times. First there was the great decanting of the urban population after World War II, encouraged by such well-meaning government programs as Federal Housing Administration and Veterans Administration mortgages and the construction of interstate highways. The supermarkets, small shops, and department stores followed, filling up the new shopping centers and malls. More recently, the office and industrial parks have followed. As early as 1980, 38 percent the nation’s workers were commuting from suburb to suburb, and only half as many were travelling from suburb to city center. Meanwhile, the poor never joined the suburban migration, becoming ever more isolated in the city core, which has become their specialized habitat.

All of this suburban development occurred under the dominion of Euclidian zoning-zoning that requires the rigid segregation of housing, commerce, and industry. That approach to zoning is a residue of the Industrial Revolution, which made it seem desirable to move people’s homes away from the dark satanic mills. Such distancing is no longer necessary, of course, since most contemporary office parks and electronics plants make extraordinarily benign neighbors. Nevertheless, every generation of planners attempts to relive that last great victory of the planning profession by separating more and more elements, more and more functions:

Even doctors’ offices today are kept strictly isolated from the people who use them.

We believe, quite simply, that all of these elements should once again be assembled into traditional towns. But what goes into the design of a town?

[Take the case of] Alexandria, Virginia, American towns share so many attributes that it could just as well be Manchester, New Hampshire, or Key West, Florida, or any number of other places. It contains neighborhoods of finite size and definite character which people can easily traverse on foot. Residential areas are seamlessly connected to the rest of the town, and they are not even exclusively residential. They boast corner stores, attorneys’ offices, coffee shops, and other small establishments.

In the traditional American town, what is important is not what buildings are used for but the buildings’ size and disposition toward the street. Buildings of similar size and characteristics tend to be compatible regardless of their use. Successful towns can be composed of little buildings, like Alexandria, or of relatively big ones, like Washington, D.C., whose buildings are all roughly the same size (thanks to strict height restrictions) though they serve a variety of functions. Some are civic buildings, others house offices, and others contain apartments. In the typical planned community, the formula is completely reversed: The building sizes vary, but the building uses are completely homogeneous. Offices go with offices, for example, never with houses.

Likewise, the streets in the two kinds of communities are conceived in completely different ways. In the planned community there are “collector streets,” which are only for cars, and cul-de-sacs, which are hard to describe because while they are supposedly designed for people they are rarely used. In the traditional town, streets are complex things, usually laid out in grids, with lanes for cars to travel and lanes for cars to park; they are lined with sidewalks, trees, and buildings. This seems like a perfectly obvious description of a street, but the fact is that we no longer design such streets. Traffic engineers now refer to trees as FHOs: Fixed Hazardous Objects. Trees, sidewalks, and buildings impede the flow of traffic; if there must be houses nearby, they are walled off by “sound barriers.”

Planned communities suffer from being. too diagrammatically planned, and at the heart of their plans is the collector street. In the traditional town’s network of streets, there are many ways to get from one place to another. In the planned community, there is only one way: A driver must make is way from his pod onto the collector, and from the collector onto the highway. Then he can go places…

All of this becomes clearer when towns are viewed from the air. The town of Virginia Beach, Virginia, for example, apparently takes pride in what it has achieved through its planning code: “Becoming a showcase, Virginia Beach Boulevard Phase One celebrated its opening,” says the caption … from the town’s promotional brochure. This is a typical product of postwar American planning as expressed through hundreds of local planning, zoning, and public-works codes. In every community, the code is a kind of constitution that lays out the rules that will order the life of the city, the rules that describe the form of urbanism that will emerge, just as the American Constitution contains within it the lineaments of American society. In Virginia Beach, as in most American communities, it is quite easy to conclude that the single most important constitutional principle is that cars must be happy. There are to be many, many lanes of traffic so that cars can move with ease and speed and negotiate turns with extraordinary grace and quickness, sparing the brakes and steering mechanism excessive wear. There is to be no on-street parking that would impede the progress of the blessed auto.

The right to park is the First Amendment in this scheme of things. Every American believes he has a constitutional right to a parking spot, even on those hectic days between Thanksgiving and Christmas. If he cannot get that parking spot, he concludes that something is dreadfully wrong and converts to NIMBYism. So there must be vast parking lots. Local planning codes describe with loving precision what the parking lots are to be like: the number of cars, the type of drainage, the kind of lights that go on them, the size of the parking space, even the paint. Our codes are extraordinarily precise about the needs of the car. But the needs of the human are another matter. The code reflects no understanding of what being in a parking lot feels like for a human being.

Everything in the Virginia Beach scheme of things is mono-functional: All of the buildings shown in the photograph house commercial enterprises-branch banks, food emporiums, discount stores-with housing and other functions carefully excluded. This is an ecological system. When all commercial activities are grouped together, the multilane roads and vast expanses of asphalt parking lot become a necessity.

Attempts have been made to repair the excesses of suburban development, and Virginia Beach illustrates some of them. There are ordinances that eliminate ugly signs, that require the preservation of trees or the planting of new ones, or that mandate the construction of sidewalks. But these efforts are largely cosmetic. Sidewalks are good for the conscience of planners, but they turn out to be so uninviting when dropped into landscapes like this that to be a pedestrian is to be considered a pariah. Driving by in a car, one might charitably offer a ride to a well-dressed person who had wandered onto this sidewalk; otherwise one would assume that a person on foot was indigent, mad, or both.

The token sidewalk reveals its absurd and perilous character most dramatically in the suburban office park, where the pedestrian is exposed to double jeopardy. On one side is roaring traffic, on the other a sea of cars. The traffic roars because the code forbids on-street parking, A line of parked cars would slow traffic and serve as a buffer of metal between the pedestrian and the moving car, providing an indispensable element of psychological comfort. Without it, the pedestrian feels too exposed. He will not use the sidewalk. Even in Paris, the great city of walkers, stores began to fail when certain avenues were stripped of their parking during the presidency of Georges Pompidou (1969-74). The hapless pedestrian is confronted by another barrier on his other side: the parking lot. It is there because the code requires it. The code requires that the building be set back a great distance from the street, and that means that the parking lot has to be placed in front. The poor pedestrian is thus deprived even of the potential interest of the building which, however miserable a structure it might be, is more interesting than the hood ornaments of cars.

There are people alive today who have never even laid eyes on the alternative to suburbia, people, in other words, who have never seen a real town. Fortunately, the American film and television myth-machine continues to do its part by churning out various simulacra of the American small town. So at least the image survives.

Authentic urban experience has become such a rarity that many places have become tourist attractions simply by virtue of being real towns. Visitors drive hundreds of miles to spend a weekend in places like Sonoma, California, just for the sake of experiencing the pleasures of small-town living.

Pondering the case of world-famous Sonoma, one realizes how pathetically easy it is to make such a place. What, after all, is Sonoma? A few very basic buildings attractively arranged. Yet tourists flock to Sonoma and places like it all over the country. Mount Dora, Florida, another tourist attraction, has two good blocks. Winter Park has four. Yet they are like magic. People come and wander around, entranced by the magic of urbanism that is denied them in the conventional suburb. This also explains the success of Disneyland and Disney World. Visitors do not spend as much time on rides as they do wandering along Main Street, USA, and the multinational urban constructions of Epcot, getting civic kicks that they cannot get at home.

Most critics of suburbia dwell on its ugliness, yet the chief defect of the suburbs is not so much aesthetic as the fact that as civic environments they simply do not work. Some of the newer and more attractive developments, such as this one in Palm, Beach, Florida, may appear beautiful, but they have insidious social effects. In this typical version of residential planning, all of the housing in each pod is virtually identical. The houses in [a nearby] pod … sell for about $350,000. Everybody who lives in those houses belongs to an economic class distinct from the one of people who live in the pod of $200,000 houses and from the one of the people who live in the pod of $100,000 apartments. The development’s layout makes random personal contact among people from different economic groups highly unlikely. No longer do we openly sanction the good old American segregation by race and ethnic group; now we have segregation by income level. It is minutely executed in the suburb, and it is consciously promoted through snob-appeal advertising. It is so extreme that the people in the $350,000 houses would rise up in arms if somebody proposed to build a $200,000 house in their pod.

Such economic segregation has far-reaching effects. A whole generation of Americans has now reached adulthood cut off from direct contact with people from other social .classes. It is now entirely possible for a child of affluence t grow up in such a class ghetto, attend an Ivy League university and perhaps a top law school, and enter the working world without acquiring any firsthand knowledge of people unlike himself or herself. As a result more and more Americans regard one another with mutual incomprehension and fear, and that accounts for no small share of the tension in our national political life.

Economic segregation is not the American way. The more traditional arrangement … in Georgetown, in Washington, D.C., allows people of different economic levels to live together. (it should be noted, however, that in Georgetown the variety is now reduced, for the simple reason that this sort of neighborhood is such a rarity and in such high demand that the poor, the elderly, and most young families have been priced out of the market.) There are small apartment buildings, relatively more expensive town houses, and single-family houses that are substantially more expensive. Across the street is a great estate. People of diverse income levels, in other words, can live very close together.

The planning techniques that make such diversity possible are simple, but most of them have fallen into disuse. One method is to match the size and mass of buildings. A large slab-like apartment building in the middle of a street of smaller dwellings instantly signals to passersby that the people living there are different from-either richer or poorer than-their neighbors. Make all the buildings roughly similar in size, however, and the size of the residents’ paychecks matters much less.

Coral Gables, Florida, built during the 1920s, demonstrates another valuable planning technique. The system of the “street address” makes use of the fact that street-level perceptions are what matter. Single-family homes exist side-by-side with larger units, but because the mass of each apartment building is tucked away behind a facade roughly equal in height and width to the houses, the differences are noticeable only from the air. A visitor driving down one of these streets would not be aware that two building types-as well as different types of people-are sharing the same geography.

The current suburban fashion, however, is to lay out sites in almost random manner. The arrangement looks more like the result of a train wreck than of a conscious design. Because the buildings face every which way, they have no real fronts or backs. Consequently, all of the buildings in the pod must be homogeneous, and that means that the people must be alike (at least in terms of income) as well.

On a traditional street, even fairly glaring differences between dwellings can be softened by close attention to architectural details. In places like Annapolis, Maryland, for example, a great historic house worth $1 million or more sits comfortably … next to a pair of tiny 12-foot-wide townhouses. The marriage works because the two structures share architectural expressions. The little townhouses have windows that are like those of the bigger house, doors that are elaborated like those on the neighbor’s house, similar roofs, and other common details.

Housing the poor in structures that look different from those of the middle class is a catastrophic mistake. Unfortunately, architects are often tempted to experiment on poor people, dreaming up novel designs for public housing. Architectural experiments should be restricted to the rich. As we discovered with the well-intentioned public-housing projects of the 1960s and later decades, people who are reminded they are different-perhaps only a few of them, but enough to have a large effect-will act differently, and before long the buildings will be in ruins.

Affordable housing must be provided in small increments and must be closely interspersed with market-rate housing. Even when it looks very much like middle-class housing, as it does in Reston, Virginia, housing for the poor quickly reproduces the conditions of the ghetto if it is concentrated in one place. On Cape Cod, there is now a requirement that 10 percent of the housing in large new developments must be affordable, which seems to be about the right ratio for achieving a mix without diminishing the value of surrounding properties.

One obstacle to spreading out affordable housing has always been the high price of land. But actually there are plenty of low-cost locations all over America. One such place is “over the store,” which in older towns such as Siasconset, Massachusetts, has long provided apartments for the clerks, cooks, or waiters who work below. It is not the American Dream to live over the store, of course, but it works. Every new shopping center built in the affluent suburbs causes a social problem, because the less well-off are forced to travel great distances to work or shop. Requiring developers to build housing above the shops would by itself put a large dent in the affordable housing problem.

Another source of land is the vast buffer strip so characteristic of suburban development. It is a reflex of modem planners to separate anything “undesirable”-office buildings, high-traffic streets, parking lots-from the rest of the landscape with a broad swath of green buffer. Why not fill in these spaces with small places designed for people who cannot afford the American Dream?

One of the oldest and most powerful tools for integrating affordable housing in communities is the humble outbuilding. In colonial Williamsburg, the house of the master sat on the front of the lot, and behind it might be a smaller house children and a little bit farther back the servants’ quarters: all on the same piece of real estate. Residential outbuildings, such as backyard cottages and garage apartments, remained a standard feature of residential neighborhoods well into the 20th century.

An outbuilding is really a bedroom pulled out of the house and equipped with a small kitchen and bath. Because children grow up and leave home, America has millions of empty bedrooms. Had some of them been built as outbuildings, they would now be available for elderly relatives, nannies, students, and many others. But suburban zoning codes completely forbid occupied outbuildings. A homeowner who submits a plan for an outbuilding will find it very thoroughly scrutinized to make sure that he cannot somehow covertly slip in a kitchen and bath. Planning authorities in other countries take precisely the opposite approach. In Canada and Australia, outbuildings are called “granny flats,” and government encourages homeowners to build them by offering tax breaks and even grants. But here we ban them.

All of this economic segregation has not even allowed us to create an Eden for those who can afford the American Dream. The modem version of the American Dream is a McMansion, which may have a well-conceived and appointed interior yet almost always lacks the advantages of a neighborhood. The McMansion is both pretentious and isolated, an island in a sea of strangers and cars. Even the much cherished suburban yard offers no more than a cartoon version of country living, utterly lacking the privacy that it promises, in part because planners have been deprived of the tools to create it.

Americans do not deserve to be treated this badly. They work very hard to achieve the American Dream. Yet in other countries with more sophisticated notions of urban design, people with incomes much lower than those of most Americans enjoy a significantly higher quality of life-not the pseudo-quality of life measured in appliances and cars but quality of life understood in terms of privacy and community. There is a renewed appreciation of these values in America, but the very tools that would allow designers to help revive them have been sacrificed to suburban sprawl.

One of the great mysteries of the American suburb is this: How with such low-density development have we produced such extraordinarily high traffic? How have we achieved the traffic of a metropolis and the culture of a cow town? That, too, has been accomplished by the miraculous postwar planning device of the collector street, festooned with its variety of pods: shopping centers, office parks, schools, and residential areas, each with an independent connection to the collector. This arrangement guarantees that nobody can go to lunch, go shopping, or get to work or school without driving.

In Orlando, Florida, it has been estimated that each single-family house generates an average of 13 car trips a day and thus vast amounts of pollution. Enormous concern about air pollution has prompted California authorities to ban charcoal-lighter fluid for home barbecues. But we keep driving. Still, it is not the 13 car trips a day that congest the streets. Asphalt abounds in the suburbs. The problem is that most of it is barely used. Instead, the suburbanite who wants to get anywhere has to make a beeline for the collector. It is on the collectors that the clogging occurs. In fact, in downtown Los Angeles, Washington, D.C., and other cities that still have 19th-century grid systems of streets, the best way to shave time off a trip is to get off the collector and use the side streets. Why? Because traffic is diffused through capillaries, rather than confined to arteries.

Compare a recent collector plan to the development strategies of the 1920s, exemplified … by Coral Gables, Florida. In Coral Gables, the closely interspersed shadings show different uses: residential, commercial, and so on. The roadways form an extraordinary capillary system that allows residents to get around easily, even on foot if they choose. Today, Coral Gables has no traffic problems to speak of, while late-vintage developments to the west of Miami, such as Kendall, are so choked with traffic that real-estate values were dropping even before the current recession. And the extraordinary thing is that the traffic from Kendall must flow through Coral Gables to get to downtown Miami.

Although some are beginning to alter their views (and their computer software), many traffic engineers refuse to believe that the old street-grid model works better. When they feed data on grid networks into their computers, the results almost always predict overloading at the intersections. In reality, the intersections are not congested at all.

An intelligently designed street system is only the first step in the creation of a workable town. The next is to figure out what it takes to get humans out on the streets, participating in the public realm. Many learned books have been written on civic life, but it is doubtful that many thinkers have greater insight into this aspect of the subject than American shopping center developers. Understanding the factors that can influence a shopper’s decision to walk from one end of a shopping mall to the other-the uses of light, the size and the proportions of spaces, the focusing distance of the human eye-is a matter of life and death to them, because consumers will take their business elsewhere if the mall does not reflect an understanding of human nature.

Some years ago, for example, we proposed putting a post office in a shopping center we were working on, but the developer vetoed it when we told him that it would have to be about 30 feet wide. He explained that people would not walk past a ring 30-foot wall; they would simply turn around without going to the stores on the other side. Design decisions that delicate.

Designers need to gain the same kind of insight into the design of housing in order to encourage pedestrian traffic on the streets. We believe that houses like this [refers to an illustration of a house close to a streetside sidewalk, a front porch and a picket fence] generate pedestrian traffic. They do so because they project the human presence within the house to those passing on the street. There is, after all, nothing more interesting to humans than other humans. While suburban developments often have a variety of pleasant features-attractive landscaping, tidiness, compatible colors-they still fail miserably at the vital task of being interesting. The reason, in this case, is that the only information these [types of] houses put forth to passersby is that cars live there. That may give passing cars a nice feeling, but it does not do much for people. It does not encourage them to get out and walk.

At bottom, this a problem of urban design: When housing achieves a certain density but parking remains a necessity, the car’s house (the garage) overwhelms the human’s house. No architect is skillful enough to make human life project itself on the facade of a house when 60 percent of it is given over to garage doors. Without them, even a mediocre architect can create a satisfactory design.

The way to banish the garage from the facade is to create an alley behind the house. This humble invention of the 19th century has completely disappeared from the lexicon of planning codes. (We once designed alleys in a Florida project but had to label them jogging “tracts” to get them accepted.) Alleys also yield an important fringe benefit: They allow residents to take their trash off the street. The decline of the alley was completed when the plastic bag was invented. Once Americans no longer had to worry about the stink of garbage, they could put it in front of their homes, which has greatly contributed to the decay of urbanism.

Alleys address another problem: where to put the “services,” the gas, electric, water, sewer, and telephone lines. Merely sinking such things underground in the street in front of the house does not solve the problem, in part because utility companies require easements that are two to 10 feet wide. Add that requirement to others-traffic lanes, sidewalks, planters for trees-and the streets become so wide that they destroy the feeling of neighborhood intimacy.

At stake in the design of streets, alleys, and other facets of the suburb, some writers say, is something they call “sense of place.” Planners are in hot pursuit of this elusive commodity, yet they seldom manage to achieve it. They seem to think that sense of place can be created by a combination of decorative landscaping, exciting architecture, varied pavement textures, elegant street lights, and colorful banners. We think that achieving a “sense of place” is a much simpler matter, better thought of in terms of sense of space. The designer’s chief task is the making of space that draws people out from their private realms to stroll and loiter with their neighbors: public space.

The ubiquitous “California-style” townhouse development is a classic case of the search for sense of place gone awry The architect wiggles the units back and forth as much as the budget will allow to individualize each one, but the result is that each unit becomes an object. They do not form a wall, and without a wall no space can be defined or demarcated. Here there is no public space; there is only a parking lot. And it should not be surprising that people flee such spaces for their homes as soon as they park their cars.

Long ago in Old Town Alexandria, Virginia, the same elements-townhouse, asphalt, cars-were put together in a much more sensible fashion. The buildings were lined up to form a wall, which defines the street as space. Each unit is distinguished by slightly varying the heights-a far more economical form of articulation. This is very simple, yet it is very rare in suburbia.

The superiority of the Alexandria model is not purely theoretical; the market shows that people are willing to pay several times as much to live in Old Town Alexandria as they are to live in a modern townhouse in a typical development, several times as much for termite-ridden beams and parking that on a good day is two blocks away. That shows how strong is the human appetite for sense of space. Any architect or planner who does not deliver such good public spaces, easy as they are to create, is not only doing our society a grievous disservice. He is doing the developer he works for a financial disservice.

Aligning buildings will not by itself yield sense of space. It is also important to maintain a certain ratio of height-to-width. From classic texts and our own direct studies of places that seem to possess this ineffable quality, we have derived a good operational rule for creating sense of space: For every foot of vertical space, there ought to be no more than six feet of horizontal space. In other words, the street width as measured from building front to building front should not exceed six times the height of the buildings.

One reason a sense of space is so rarely achieved in this country is that Americans like their houses low and their front yards deep-a formula for exceeding the ratio. But even this can be mitigated, as it is in many older suburbs, by the use of trees to humanize the height-to-width ratio. The woman riding her bicycle [refers to a photo of a woman riding a bicycle on a shaded residential street] is having a more pleasant day because somebody long ago had the good sense to plant rows of trees. That underscores the fact that in the suburbs, landscaping is not just a form of decoration; it is a social necessity. In traditional town planning, landscape architects first correct the spatial problems created by the planners and architects and only then make pretty scenes. Yet today most of them would rather die than line up trees in a row. It is considered uncreative. They would rather design beautiful naturalistic clusters, hoping to foster the illusion that a forest had somehow sprouted in the middle of the city.

Another obstacle to a sense of space is the curvilinear street, perhaps the most common feature of the suburban subdivision. On a perfectly flat piece of land, the roads twist madly, as if they were hugging the side of a mountain. Streets ought to be laid out largely in straight segments, as they were until the 1940s. After all, the vast majority of our successful towns and cities, from Cambridge to Portland, were laid out this way. Yet we have twice been summarily fired by developers when we submitted plans that included grids. Upon reflection, we realized that the developers had a valid concern, one related to the shopping-center developers’ understanding that human beings do not like endless vistas. People do not like to look down a street without being able to focus on its end.

The curvilinear street seems a natural solution, since it constantly closes the vista. But it has unfortunate side-effects. A landscape of curvilinear streets is disorienting (which is why the visitor to the suburbs constantly has the feeling of being lost). Curvilinear streets also prevent the eye from focusing on anything for longer than a fraction of a second. And since the human eye needs at least two or three seconds to perceive architectural gestures-the memorable pediment or facade, the steeple-architects do not bother to provide them. Without such landmarks, the neighborhood becomes a featureless mass of buildings.

Again, it requires no great creative gift to discover alternatives that work with grids. One notable town-planning manual published in 1909, Raymond Unwin’s “Town Planning in Practice,” contains page after page of illustrations showing the many ways that intersections can be cleverly used to terminate vistas. In the memorable American cities, such as Charleston, South Carolina, our ancestors even used intersections as sites for churches, civic buildings, and other special structures, and these are the very sites that have become famous and that draw tourists from all over. Today, it would be impossible to build such intersections, because they have been outlawed as threats to public safety at the behest of the traffic engineers.

In fact, it is often the odd intersections that produce the fewest accidents. When we drew up a master plan for Stuart, Florida, the authorities immediately proposed straightening out the town’s “confusion corner,” an intersection so tangled that a picture of it graces a postcard. But our research showed that “confusion corner” ranked only 20th for traffic accidents in Stuart. The 19 more dangerous intersections were built to contemporary engineering standards. In Washington, D.C., according to one local architect, 11 of the 12 most dangerous intersections conformed to such modem standards. It is not hard to guess the explanation. A driver on the enormous streets that are now mandatory is more likely to be bored and inattentive (and possibly speeding) than is a driver on a “dangerous” older street.

Grids, intersections, and other devices are important, but other details must be attended to in order to bring people out into the civic realm. One of the most important is the curb radius at intersections. At the now standard 25-40 feet, the curb radius allows the driver of a car travelling 35 miles per hour to negotiate the comer without having to slow down much. That poses an intimidating challenge for a pedestrian attempting to cross the street. Moreover, the gentle curve of the sidewalk, so kind to the car, nearly doubles the pedestrian’s crossing distance. A 24-foot-wide road widens to 40 feet where pedestrians cross. Priority has been given to the car, not the pedestrian.

Pedestrians count in places like Boca Raton, where a typical curb radius is eight feet. In Boston, radii of eight or six or even three feet are very common. A typical traffic engineer will swear that such a thing is no longer possible, that it will cause accidents. But it does not.

Common sense has evaporated from the traffic-engineering profession, and the huge costs of its absence are measured in economic as well as aesthetic terms. In America, thanks to the traffic engineers, we push highways right through the middle of cities, as [the] cover of Florida’s Department of Transportation annual report proudly demonstrates. By giving a little four-lane road in Orlando the characteristics of a highway, the state turned it into a monster. Highways destroy cities. When it enters a town or city, a highway should become a boulevard. A typical French boulevard actually has more lanes than the Orlando highway [refers to a photo of one with 12], but an entirely different effect. The elements and engineering “geometries” of the boulevard are completely different. Buildings and trees line the boulevard and cars park along its length, inviting pedestrians to stroll along its sidewalks.

American taxpayers would be astounded if they realized the true costs of their highways, costs that far exceed the price of construction. Avenues help pay for themselves by enhancing the value of buildings in the vicinity and thus enlarging the tax base. But highways destroy market value and shrink the tax base, forcing local authorities to raise tax rates. Their hidden costs probably run into billions of dollars.

In the United States, we invest too much in “horizontal infrastructures and not enough in “vertical infrastructure,” too much in asphalt on the ground for cars and not enough in buildings for people. Our planning codes and regulations demand a gold-plated asphalt infrastructure, leaving little money for the human infrastructure. The unhappy results are all around us. Some of us have become quite accustomed, for example, to sending our children to schools that are nothing more than trailer parks with fences around them. But the highways are built to ever higher standards; they are wider, the curbs are softer, the concrete more elaborate. Everything gets better for the cars; we do not dream of denying our automobiles anything.

Building more highways to reduce traffic congestion is an exercise in futility. Whenever it is done, more people are encouraged to take to their cars, and before long the roads are as clogged as ever. We cannot continue to spend as extravagantly on roads as we did during the postwar decades of affluence. We must revert to planning approaches from the days when America was a poorer but smarter nation. The only permanent solution to the traffic problem is to bring housing, shopping, and workplaces into closer proximity.

Reining in the auto would also help solve the problem of affordable housing. At MIT, architects are going to great lengths to find ways to make housing cheaper, developing prefabricated components, spacing wall studs further apart, and using rubber hoses for plumbing. In the end, all of these efforts do not add up to very much-perhaps a $10,000 or $20,000 savings. Nothing can be done that rivals making it possible for a family to get by with one less car. That extra car, so necessary in today’s suburb, costs about $5,000 annually to operate. That is a highly leveraged sum, large enough to supply the payments on a $50,000 mortgage at 10 percent interest.

The tyranny of the auto reaches into every comer of American life. Why is the U.S. Postal Service perennially bankrupt? One reason surely is that it has to deliver mail all over the continent in broken jeeps. The auto’s worst victims, however the very young and the very old. Every year, hundreds of thousands of people move to Florida and many thousands move out.

Many of those emigrants are people who moved to Florida to retire but found after a few good years that they had to go elsewhere. The suburb, they discovered, is poorly suited to the elderly. A suburbanite who loses his or her driver’s license -perhaps because of failing eyesight-ceases to be a viable citizen. That person cannot go shopping, visit friends, or get to the doctor’s office. He cannot take care of himself. In a town, he can. He may be too old to drive, but he is not too old to walk. Unfortunately, only a few senior citizens are wealthy enough to afford to live in the rare towns that exist-some of these have been dubbed Naturally Occurring Retirement Communities, or NORCS, by demographers. For the less-fortunate majority, nursing homes are frequently the only alternative.

Children are the other great victims of the suburbs. Families move to the suburbs precisely because they are supposed to be “good for the kids.” And the fresh air and open spaces are good for them. Suburban sprawl is not. Children in the postwar suburbs are kept in an unnaturally extended state of isolation and dependence because they live in places designed for cars rather than people.

The school is the social center of the child’s life, but the routine of the typical suburban school is governed by the school bus. The children are bused in at eight o’clock in the morning and most of them are bused home at three o’clock, regardless of what they are doing, warehoused in front of television sets until their parents come home from work. If the parents do not want their children to lead that kind of life, one of them (almost always the mother) has to stay home to take care of them. And that often amounts to little more than exchanging a career for a new job as an unpaid chauffeur. Imagine how the lives of children would change if the suburban house and yard were assembled in the form of a traditional neighborhood so that kids could visit friends, go out for a hamburger, or walk to a library on their own.

All of us suffer. The eight-hour workday was the great victory of the past century, but we have, squandered our gains by expanding our commuting time. Instead of spending two more hours a day with our families and friends, or forging bonds of community over the backyard fence or at the town hall, we have chosen to spend them competing with our fellow citizens for that scarce commodity called asphalt. That is yet another example of how the public realm has been transformed into an arena of hostility and competition.

Americans are ready for the return of the town. The signs of a revival of interest in community on a smaller scale are everywhere. In major cities, policemen are deserting their patrol cars and walking the sidewalks, not just responding to crises but actually getting to know the people on their beats, The experts have dressed this up by calling it “community policing.” New York City is studying the possibility of decentralizing its courthouse system, creating 75 precinct courthouses so that the legal system is brought closer to all citizens. Corporations are moving to small towns; Los Angeles yuppies by the thousands are leaving the city’s sprawl for the more traditional neighborhoods of Portland and Seattle.

Developers are starting to catch on to this reality. During the 1960s, most of their advertising appealed to snobbism; during the ’70s it emphasized security; now “community” sells. The marketing experts at Arvida, the largest and probably the most sophisticated developer in Florida, have promoted one of their new developments, Weston, by calling it a “hometown” and advertising various “lifestyle attractions.” But developers are cautious because Americans seem to have been so happy buying houses strewn amid suburban sprawl. Arvida, like other developers that have taken this tack, did not actually build a town. Weston is much the same as any other suburban planned community, with the usual shopping and housing pods connected to collector streets.

Building real towns will require changing master plans, codes, and road-building standards, and, above all, attitudes. The mindless administration of rules enshrining the unwisdom of the past half century must cease; the reign of the traffic engineers must end. Americans need to be reacquainted with their small-town heritage and to be persuaded of the importance of protecting the human habitat every bit as rigorously as the natural habitat. Architects and planners and developers can be leaders and educators, but ordinary citizens will have to insist that the happiness of people finally takes precedence over the happiness of cars, that the health of communities takes precedence over the unimpeded flow of traffic. As the great architect Louis Sullivan wrote in 1906:

“If you seek to express the best that is in yourself, you must search out the best that is in your people, for they are your problem, and you are indissolubly a part of them. It is for you to affirm that which they really wish to affirm. Namely the best that is in them. if the people seem to have but little faith, it is because they have been tricked so long. They are weary of dishonesty, more weary than they know, much more weary than you know. The American people are now in a stupor. Be on hand at the awakening.”

These were hopeful words in 1906. Nearly a century later, they are urgent.


Does Free-Flowing Car Traffic Reduce Fuel Consumption and Air Pollution?

Cities and Automobile Dependence (1989)

by Jeffrey Kenworthy and Peter Newman

Kenworthy and Newman, in this landmark book, argue from their worldwide survey of cities that the goal of “free-flowing” traffic (through such strategies as road widenings) actually results in MORE fuel consumption and air pollution.

“Does free flowing traffic save fuel (and lower emissions) in a city? This question is often asked in response to our contention that traffic [calming] will ease automobile dependence and gasoline use; it is generally asserted that building up congestion will in fact make cars use more fuel and we will be worse off than before…There is a longstanding observation that automobiles get high miles per gallon in smooth, free-flowing traffic and poor miles per gallon in stop-start, congested traffic…”

One form of research bias is that of looking only at the emissions from individual cars, and not taking into account the inevitable changes in travel behavior that result when cars move faster and more freely. When conditions change to allow easier use of the car, people will inevitably drive more often and further, and are more likely to use a car instead of walking, bicycling or using the bus. This is because it becomes more unsafe and unpleasant to walk, bicycle, or ride the bus when travel by car is easier and more frequent. In other words, car travel tends to be a “zero sum game” — that is, when we design our streets to improve conditions for cars, we almost inevitably worsen things for other forms of travel.

“…research treats the road traffic system as an independent factor, capable of being modified in isolation from feedback effects within the rest of the urban system, for example changes in land use patterns…

…[However], it is cities with the highest average traffic speeds that have the highest per capita gasoline consumption…congestion…increases progressively as gasoline use declines…

…while congestion diminishes significantly from central to outer areas (e.g., speeds improve 54 percent) and vehicle fuel consumption improves, actual per capita fuel use by residents in these areas increases significantly. Vehicles in central areas have 19 percent lower fuel efficiency than the Perth [Australia] average due to congestion but the central area residents use 22 percent less actual fuel, and conversely, congestion-free outer suburban driving is 12 percent more fuel efficient than average but residents use 29 percent more actual fuel…

…the feedback parameters such as land use factors and [forms] of travel exert an influence on gasoline use far in excess of the fuel efficiency of vehicles as determined by traffic conditions. In other words, in the congested but denser and more compact central and inner areas travel distances are shorter for all [forms of travel] and there is greater use of [transit], walking and cycling.

…while vehicles driven in the Perth central area at [21 mph] average speed have 17 to 27 percent more hydrocarbon and carbon monoxide emissions respectively per [mile] of travel relative to the average for Perth, residents of the area actually generate 19 to 21 percent less total carbon monoxide and hydrocarbons respectively due to their smaller use of the automobile and greater use of other modes…residents of the outer suburbs actually generate some 24 to 27 percent more carbon monoxide and hydrocarbons respectively than the average…higher average vehicle speed appears to spread the city, creating lower density land use, a greater need for cars, longer travel distances and reduced use of other less polluting or pollution-free modes. The benefits gained in terms of less polluting traffic streams appear to be overwhelmed by the sheer amount of extra travel and resulting bulk of emissions…Barry et al., showed that it is the lower density, more automobile oriented US cities that have the worst total environmental pollution…

…the central focus needs to be on automobile dependence rather than any tinkering with how well a vehicle is performing in the traffic stream. Land use patterns which give rise to automobile dependence…are usually promoted by most attempts at easing congestion and are thus counterproductive in the longer term…extra speed is not used to save time but to travel further in response to more far flung land uses, and this extra travel involves time expenditure in excess of that saved by travelling faster.”

(pg 142-159)

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.


*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.



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.


An Economist’s View of Road Concurrency

In June 1989 in Orlando, professor Ronald G. Holcombe of Florida State University made the following comments regarding road concurrency in the State Growth Management Law. In general, they track what Anthony Downs had to say regarding his “triple convergence” theory. I believe these comments will be extremely important to keep in mind:

One implication is that levels of service, as defined by Florida Administrative Code Rule 9J-5, may be impossible to implement. Road improvements intended to raise the level of service could result in increased levels of traffic instead.

It could make sense to have temporarily lower levels of service in areas of new development.

More congestion would make it easier to implement mass transit in an area. Mass transit could improve levels of service without direct roadway improvements.

…Economic principles suggest that people should pay for the infrastructure they use. This imposes costs on users, causing them to take account of the costs of their own actions.

One implication is that gasoline taxes are a better source of revenue for roadway improvements than other sources such as sales (or income) taxes.

…the last development built that adds traffic to a road is not the development that causes the congestion. All traffic on the road, whether from new or old developments, are equally responsible for the congestion on roads.

…If this principle is not adhered to, it creates a common pool problem (with the arterial road being the common pool). Everyone has an incentive to develop property too fast so as not to be the one who is charged for congestion on the roads. Thus, a policy of taxing new development more than existing developments for common infrastructure will lead to overly rapid development, helping to cause congestion problems that the policy is intended to solve.

This will make it impossible in some areas to alleviate congestion by enlarging capacity. There is a fallacy that sometimes creeps into highway planning that a given amount of development will create a given amount of traffic. In fact, the amount of traffic created by a given development depends upon how costly it is to use the roads. The mere act of enlarging capacity will create congestion without additional development by reducing the incentive to avoid peak hour travel, creating the incentive to take more trips, and reducing the incentive to live close to work. Congestion is a cost that rations roadway use, and it follows that unless tolls are charged, congestion cannot be eliminated from intensely populated areas by enlarging roads.