Looking at the Big Picture | Nov 7th at 11:48am
I’m currently enjoying a session on regional urban planning featuring Dinesh Mohan, who is a professor in the Transportation Research and Injury Prevention Programme at the Indian Institute of Technology in Delhi. Mohan has made a number of excellent points concerning the structure of cities in shaping vehicle speeds and willingness to walk and use transit, and the extent to which those variables influence both carbon output and public safety. These are issues that Jane Jacobs popularized—that if we don’t make city structures inviting to people, to do all the things they do, then they’ll stay away, leaving the streets for automobiles with all of the associated safety and environmental issues.
I am struck, however, by one idea that Mohan has pressed. He suggests that underground transit does nothing to impede automobile flow, but merely increases supply. As such, driving is not much reduced by transit construction. He thinks, in fact, that rapid, high-capacity transit inside cities is not a good use of money.
I can’t agree with this, for several reasons. For one thing, increased transportation supply is desirable, for its own sake. Cities are economic engines that bring resources together to create wealth. This is a good thing, and fast, effective transit is an excellent means to keep economies healthy in a green fashion. But it’s also important to take a view of transit that considers a bigger picture. Improved transit systems reduce the relative cost of taking transit, compared to driving. This provides an incentive to shift land uses to take advantage of that improvement in relative costs—changes that can increase walking and biking. Where transit is used as a tool to alter the shape of cities, and this is increasingly a priority in many growing American cities, the economic and environmental return can be great. Denying people transit in big cities will lead them, by and large, to drive more. When congestion becomes an intolerable problem, those people may move closer to their jobs, but they may also move elsewhere, to a younger, more highway-rich city. Denying people good rapid transit is entirely counter-productive to the effort to build walkable blocks and reduce auto-dependency.
It’s also important to remember that transit is far less competitive than it should be, relative to driving, because of the favoritism we show to automobiles. We allow drivers to use roads at no cost in most cases, leading to congestion. We provide massive volumes of parking. We build at low densities that make walking problematic.
The city structures Mohan discusses are vital, and they are intimately connected to transit. Each helps shape the other, and neither should be viewed as a solution in and of itself.
Ryan Avent is an economics writer living in Washington, DC. He authors The Economist's economics blog, Free Exchange, and covers environmental and urban policy issues for Grist.
