Abstract
The transit industry has experienced great declines in ridership since World War II from which it has recovered only partially since the 1990s. By contrast, commuter rail has flourished as a result of suburbanization, strong downtowns, and continued public support. With a focus on older systems, the study reported in this paper reviewed changes in population, downtown employment, and ridership and related these changes to the ways in which technology, public policy, ridership, and operations have affected commuter rail. Since about the 1990s, the number of commuter rail passenger miles in the United States has grown faster than the number of national highway vehicle miles traveled. Modern commuter rail ridership has reached (or has surpassed) the historic peak levels reached in 1929. Commuter railroads have met the demands of growing ridership through the use of cars with higher seating capacities, which have provided more frequent off-peak service, and through the adoption of such innovative operating plans as zone schedules. Even the rehabilitation of deteriorated tracks sometimes has helped to increase train throughput. Such improvements have enabled commuter railroads to accommodate more customers, although capacity will have to be increased where severe constraints exist. Continued public support will be essential to the future of commuter rail in most metropolitan areas.