Eric Jaffe at Citylab writes: Public Transit Does Not Have to Reduce Traffic Congestion to Succeed. An excerpt below …

A Political Economy of Access: Infrastructure, Networks, Cities, and Institutions by David M. Levinson and David A. King

Expect plenty of other benefits

Good transit offers a world of benefits beyond any impact on rush-hour roads, beginning with agglomeration—the economic boost that occurs when people and jobs cluster in cities. Once a city reaches a certain level of congestion and hits a wall in terms of road space, rail or bus systems are the only way to pump more people into the central areas that produce these gains. Here’s Jarrett Walker on how transit “raises the level of economic activity and prosperity at a fixed level of congestion”:

Congestion appears to reach equilibrium at a level that is maddeningly high but that can’t be called “total gridlock.” At that level, people just stop trying to travel. If your city is car-dependent, that limit becomes the cap on the economic activity — and thus the prosperity — of your city. To the extent that your city is dependent on transit, supported by walking and cycling, economic activity and prosperity can continue to grow while congestion remains constant.

Other benefits to transit include better overall access to the city (especially jobs), greater mobility for people who don’t drive (for reasons of choice, health, or income), and of course improved sustainability. There’s a basic equity issue here, too, captured by transport scholar David Levinson in a great essay earlier this year at streets.mn explaining why “it warps thinking that the aim of public transit funding is to benefit those non-transit users”:

Transit today is, in almost all US markets, slower than driving. People who depend on transit can reach fewer jobs than those who have automobiles available. Some people use transit by choice, for instance to save money (if they need to pay for parking), and the rest without choice. In my opinion, it is more important to spend scarce public dollars to improve options for those without choices than to improve the choices for those who already have alternatives.

There is a way to relieve traffic congestion: charge drivers to enter high-traffic areas at high-traffic times. Congestion pricing has worked everywhere around the world it’s been implemented. But since not everyone is able or willing to pay a road fee, congestion pricing requires something besides the right price to succeed—namely, good public transit alternatives.