University of California Transportation Center

When a city requires on-site parking for all new housing, housing costs rise while the price of driving falls. This results in less housing and more driving. Minimum parking requirements are particularly troublesome for old, dense inner city neighborhoods. Many buildings constructed before World War II don’t have parking attached to them, and in dense center cities—where land is expensive, and lot sizes are small and irregular—parking can be extraordinarily expensive, if not impossible, to provide on-site. Thus many older in-city buildings sit unused, simply because they can’t provide enough parking to satisfy the zoning code.

Measuring how parking requirements affect housing construction is difficult for a simple reason: parking requirements are everywhere. There is good theoretical reason to believe that relaxed parking requirements would result in more housing, and developers regularly say that left to their own devices, they would supply less parking. But because developers are almost never left to their own devices, the theory is hard to test.