Recent studies and analysis indicate that in order to increase the likelihood of success, high speed rail must reach into the center of cities. These studies indicate that under the lowest ridership projections, high speed rail may not result in a net decrease in green house gasses, even over thirty years, when taking into consideration construction and operation, compared to automobile and air travel. However, if ridership is high, a net decrease in green houses gasses may be experienced within eight years of operation.
Therefore, according to Petra Todorovich, Director of America 2050, it is imperative that high speed rail offer something distinct from air and auto travel in order to provide a competitive alternative mode of travel. Airports tend to lie on the outskirts of city centers and automobile travel is subject to the uncertainty of traffic congestion and involves more time over longer distances. Therefore, in order to be competitive with these travel mode alternatives, high speed rail, which offers speed similar to air travel, must provide direct center city connections not offered by air travel.
This is especially true in the western U.S. with lower population densities sprawled-out over greater areas. Additionally, these studies demonstrate that it may not be viable to simply offer high speed rail transit as an alternative form of travel to compete in the transportation marketplace on a “level playing field” with air and auto travel, i.e., while expenditures on highway and airport construction are given a similar priority. Rather, these studies demonstrate the need for a public policy commitment that shifts planning and transportation expenditures decisively in favor of rail transit in order for it to be successful.
See also article by Saqib Rahim (New York Times, July 19, 2011), Who Will Ride an Alternative to ‘Market-Driven Sprawl’?