To most people, traffic jams look like an ecological disaster. And they are one, but not for the reasons that people assume. Here’s why: Traffic jams are not an environmental problem; they are a driving problem. If reducing congestion merely makes life easier for those who drive, then the improved traffic flow actually increases the environmental damage done by cars, by raising overall traffic volume, encouraging sprawl and long car commutes, and reducing the disincentives that make drivers think twice about getting into their cars.
Traffic jams are actually beneficial, environmentally, if they reduce the willingness of drivers to drive and, in doing so, turn car pools, buses, trains, bicycles, walking, and urban apartments into attractive options.
Treating congestion, rather than driving, as an environmental issue often leads to transportation policies that, from an environmental point of view, are flawed. Almost always, when traffic engineers and others talk about reducing congestion what they are really talking about is making traffic flow more efficiently, and that means increasing the overall volume of cars—an obvious environmental negative.
The metropolitan New York area accounts for more than a third of all the public-transit passenger miles traveled in the United States. The city’s subway system is the third busiest in the world, after those in Tokyo and Moscow, and its routes encompass almost half of all the subway stops in the United States.
New Yorkers don’t use transit because they’re more enlightened or more environmentally aware than other Americans; New Yorkers use transit because owning and driving a car in the city is almost ridiculously disagreeable. Curbside parking is scarce, and parking lots are shockingly expensive and, often, inconveniently situated or hard to find. Most important of all, the average speed of crosstown traffic in Manhattan is little more than that of a brisk walker. At certain times of the day, in fact, the cars on the side streets in midtown move so slowly that they appear almost to be parked.
Most people, including most New Yorkers, view such clogged streets as an urgent environmental problem, since the cars seem to just sit there, spewing exhaust. But traffic jams like those actually generate environmental benefits, because they urge drivers (and cab riders) either into the subways or onto the sidewalks. Making car use more attractive than the subway, by reducing the congestion on the streets, would be a loss for the environment, not a gain.
