Congestion and Traffic Safety

By Dom Nozzi

Reducing Congestion

I’ve heard Andres Duany, one of the great urban thinkers of our generation, make this first point in a speech long ago, but just read it again in a book I recently read called Common Place, by Douglas Kelbaugh.

Kelbaugh informs us that “…the Southern California Association of Governments, including some 30 municipalities around Los Angeles, commissioned a computer simulation of traffic in the year 2010. It modeled many possibilities, among them double-decking highways, additional lanes, expanded bus and rail transit service, and staggered work hours. They concluded that nothing that could be done to add capacity to the system would have a lasting effect on congestion—except for one strategy that was not a transportation fix per se. Mixed-use neighborhoods, because they eliminate the need for trips in the first place, were found to offer a permanent solution to traffic congestion…”

I have two observations about this crucially important insight. First, as you might guess, I’m not sure why an urban area would want to reduce traffic congestion, given all the superb benefits congestion effectively delivers. To be charitable, it is possible that what is meant here is that mixed-use neighborhoods effectively allow people to escape the congestion that exists. Being able to escape congestion is more achievable (compared to being able to reduce it). Escape tactics are generally useful for building a quality, sustainable community: Connected and tightly gridded streets. Higher density, mixed-use development. Low-speed street design. Buildings abutting sidewalks. And so on.

Secondly, I am firmly convinced that achieving mixed use, higher density development (which is nearly absent in most every community in America) can only occur when large numbers of residents desire it. And that is highly unlikely in these days of subsidized cars, suburban homes and gasoline. athens GA walkableCitizen desire comes from traffic congestion, toll roads, priced and scarce parking, relatively high gas costs, low-speed roads that are no more than 3 lanes in size, and land development regulations (LDRs) that make such compact, low-speed development legal (such LDRs are nearly non-existent in American communities).

All of the elements that many of us desire in a community (well-used transit, well-used bike lanes, well-used sidewalks, less per capita SOV travel) come after we put the necessary pre-conditions in place (density, mixed use, expensive parking & driving). Better transit, more bike lanes, more sidewalks will be ineffective as ways to induce more transit use, bicycling and walking. I believe that communities largely assume that more buses, more bike lanes and more sidewalks will result in more transit use, bicycling and walking because those factors are more under the control of a local government. The truly effective tactics are less under the control of local government. If all you’ve got is a hammer, all your problems look like nails…

Traffic Safety

According to the National Highway Traffic Safety Administration, 80 percent of all car crashes are due to inattentive drivers.

Knowing this, what would be the worst possible way to design streets?

How about using a street design theory that encourages motorists to drive without paying attention—that is, a design that “forgives” a motorist for driving inattentively?

What has been the street design paradigm for the past 100 years?

The “forgiving street” paradigm.


Is it any wonder why we have an epidemic of inattentive driving in America? Isn’t it inevitable that “forgiving street” design has created a road safety nightmare?

The bitter irony is that this paradigm is what traffic engineers are taught is the primary means of creating traffic safety. But what should have been obvious is that forgiving street design enables drivers to be “forgiven” for driving too fast, too recklessly, and too inattentively. The result of forgiving streets is that we have an epidemic of inattentive drivers putting on make-up, talking on the cell phone, and casually driving 80 mph. And that means we are seeing declining driving skills and a growing number of crashes on roads that are increasingly unsafe to walk or bicycle on (or drive a car on).

cell phone while driving

The idea persists because it is commonly thought that safer streets would be those where we assume drivers are inevitably incompetent morons. So we design the street so that we reduce the consequences of driving like a moron. Common sense, right? It becomes a powerfully self-fulfilling prophecy. Forgiving streets have spawned an exponential growth in moronic driving. Americans are now perhaps the worst drivers on earth.

I don’t buy the argument, by the way, that American drivers are genetically predisposed to drive like morons to explain why American driving is so awful. It is nearly certain that bad driving in the US is almost completely due to the consequences of driving on forgiving streets.

Isn’t it highly probable, in other words, that after 100 years of designing forgiving roads, traffic engineers have been responsible for an enormous growth in the amount of inattentive driving by motorists?

Isn’t it time we strive for improved driving skills, rather than assuming moron drivers? That we adopt the Moderman concept of “naked streets” if we truly want more traffic safety in the long run? Or what I call “attentive streets,” where we obligate the motorist to pay attention?



Visit my urban design website read more about what I have to say on those topics. You can also schedule me to give a speech in your community about transportation and congestion, land use development and sprawl, and improving quality of life.


Or email me at: dom[AT]

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1 Comment

Filed under Bicycling, Urban Design, Walking

One response to “Congestion and Traffic Safety

  1. yason

    An excellent summary! I know you’re on the right trail with regard to this.

    It just makes me wonder that what on Earth can be done about it, except moving all people to Netherlands and assimilating them into the Dutch mindset? But in practical terms? Short of an economical or energy catastrophe then what could, in actuality, change the world by 2050? Or 2025?

    Oh, and about “forgiving streets”: sounds very much like an analogy to “Make something an idiot can use and only idiots will use it…”


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