By Dom Nozzi
There is a profound paradigm shift going on in transportation planning.
The conventional thinking (that I reject quite vigorously) concludes that the way to effectively ease congestion, excessive energy consumption and air pollution problems is to: 1. Increase road capacity by adding travel lanes and turn lanes and one-way streets; 2. Enhance “free-flowing” conditions for cars with timed signal lights, wider streets, and other techniques that reduce “friction”; 3. Provide abundant and free parking at all urban destinations so that people will not have to “hunt” for a place to park; 4. Build cleaner, more fuel efficient vehicles.
You will notice that none of these techniques do anything to modify unsustainable American behavior towards more sustainable behavior. Nearly all engineers and politicians in America have always believed it is “unAmerican” to do things to modify behavior so that behavior is more socially responsible and sustainable.
Instead, the engineer does what he or she is trained to do, and that is to tinker with the technology to solve problems. When all you have is a hammer, all problems look like nails.
Engineers tend not to have any training in human behavior. Such behavior modification, traditionally, is not thought to be compatible with a “free” society. Only totalitarians would do that, after all. This is the thinking of many utility company engineers, who generally believe the solution to energy and water problems is to increase the supply of energy and water, rather than employ effective conservation strategies.
The newly emerging paradigm in transportation and environmental management, by contrast, is that solving problems by increasing supply (rather than reducing demand) is not sustainable. We must do things that modify behavior (sometimes called “demand destruction:) so that behavior is more sustainable.
One very effective way to do this is with pricing, and if the market cannot properly price scarce or vulnerable ecological and other resources, we need government to step in. When it comes to transportation, we need to use both pricing and scarcity to modify demand toward sustainability.
What conventional engineers and elected officials did not know (or were happy to ignore) is that, say, increasing road capacity (road widenings, turn lanes, etc.) or providing more free and abundant parking (and other forms of transportation subsidies) totally swamps any gains we might realize in terms of reducing “stop and go” traffic, or in terms of getting more “free-flowing” traffic. Why? Because increasing transportation facility supply makes it easier and cheaper to unsustainably drive a car everywhere, which modifies behavior in an unsustainable direction.
We do nothing to discourage “low priority” motor vehicle trips, such as a drive across town on a major road to rent a video. With the heavy subsidies to enhance supply, we almost beg people to make such trips and live in remote, sprawlsville locations.
As a result, many recent studies are finding that increasing supply (primarily by widening roads with more travel lanes or turn lanes) eases congestion for only a tiny period of time, after which the congestion becomes worse than before we spent millions of public dollars to “correct” the problem.
The most concise, profound explanation of this comes from Anthony Downs, who calls it “The Triple Convergence” in his book, Stuck in Traffic. The Triple Convergence inevitably emerges when we add capacity to our transportation system, so every time we add capacity by widening roads, we make induce new 
car trips that would not have occurred had we not increased road supply via widening. Indeed, within a few years, congestion often becomes worse than before the road widening was created.
An important corollary here is that transportation drives land use. It is our transportation system that will determine if we have sprawl into our outlying, environmentally sensitive areas¬—not regulations, land use plans, or enlightened politicians.
Increasingly, therefore, honest and informed researchers and planners are referring to the problem of “induced demand,” in which we always see more vehicle trips created after widening roads.
Note that it is apparently it is “okay” to modify demand when it moves us toward unsustainable consumption.
Informed researchers and planners increasingly call for “planned congestion,” in which we allow congestion to “worsen.” Because of the “time tax” created by congestion, “planned congestion” tends to be a very effective way to get compact development, discourage sprawl, reduce air pollution, and reduce gasoline consumption. Because congestion discourages motor vehicle trips (and encourages bicycle, bus, carpool and walking trips), research now shows that more congested areas (on an area-wide basis) produce less air pollution and gas consumption.
Because this seems so counter-intuitive and non-sensical, politicians, engineers, and real estate people (who benefit from unsustainable transportation and sprawl) can get away with claiming that road widenings, turn lanes, and free and abundant parking will reduce air pollution and gas consumption.
But it is just not true.
This misguided conclusion ignores the behavior-modifying effects of increasing the transportation facility supply, which utterly overwhelms the minor benefits to individual cars of enhancing free-flowing traffic. When we take into account the system-wide impacts and behavior modification that occur when we do things like widen roads, we find that the emperor is wearing no clothes.
Transportation is truly a zero-sum game.
Nearly always, if not always, when we make it easier to drive a motor vehicle, we make it harder to travel another way, which profoundly modifies behavior. We should not be fooled into thinking it is inevitable that we are all doomed to live a life of extreme auto dependence, wherein we are forced to make every trip, no matter how trivial, by car.
So in conclusion, we need to be very, very careful when we hear claims that it is best to solve congestion, energy, and air pollution problems by making it easier and cheaper to drive a car.
My opinion is that the millions we spend to do that only make things worse.
Long ago, I read a profound, disconcerting quote on the behavior modification issue. Unfortunately, I do not have the name of the author: “Throughout history, whenever a culture had to make a decision between fundamentally changing its behavior, or to become extinct, it has always chosen extinction.” Let us hope that we are the first not to follow that path.
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