"NOBODY GOES THERE to eat anymore," the legendary baseball star and malaproprist Yogi Berra once said about a St. Louis restaurant. "It's too crowded."
We laugh at the ingenuous irony in Berra's words: His remark simultaneously contradicts itself, yet makes intuitive sense. Obviously the restaurant is crowded because customers are going there. On the other hand, who wants to go to a restaurant that's always crowded?
Transportation planners talk about busy highways in much the way Berra quipped about packed restaurants. Highways are too congested, they say, so why build more of them? Add new traffic lanes and they'll just fill up too. This is the doctrine of "induced demand" — the belief that traffic, like gas, expands to fill any available space, and that it is therefore futile to imagine that highway overcrowding can be relieved by building more highways.
In many circles, this has become unassailable dogma. In a 2014 article in Wired ("Building Bigger Roads Actually Makes Traffic Worse"), Adam Mann put it concisely: "New roads will create new drivers, resulting in the intensity of traffic staying the same." At Streeetsblog, a leading anti-automobile, pro-transit website, Tanya Snyder was even more concise: "Roads cause cars."
To induced-demand true believers, enlarging a highway is as primitive and ineffective a cure for congested traffic as bloodletting was for cholera. Adding highway capacity may briefly speed up traffic flows, they argue, but new drivers quickly slow it back down. Before long, the new lanes are just as congested during rush hour as the old ones were. "Trying to solve congestion by making roadways wider," says urbanist Charles Marohn, "is like trying to solve obesity by buying bigger pants."
But the simile is wrong. Our snarled roadways are less like obesity, an unhealthy condition to be treated and overcome, than like a teen's growth, a natural development to be welcomed and accommodated. . . .