Cities that expanded their rail systems significantly outperformed cities that only expanded bus systems in terms of transit ridership, passenger-mileage, and operating cost efficiency

Abstract
There is ongoing debate over the relative advantages of rail and bus transit investments. Rail
critics assert that cities which expand their bus transit systems exhibit better performance than
those that expand rail systems. This study examines those claims. It compares public transport
performance in U.S. urban areas that expanded rail transit with urban areas that expanded bus
transit from the mid-1990s through 2003, using Federal Transit Administration data. This
analysis indicates that cities that expanded their rail systems significantly outperformed cities
that only expanded bus systems in terms of transit ridership, passenger-mileage, and operating
cost efficiency. This indicates that rail transit investments are often economically justified due to
benefits from improved transit performance and increased transit ridership.

http://www.vtpi.org/bus_rail.pdf