Blurring the Light Rail Transit-Bus Rapid Transit Boundaries Rapid Light Transit

摘要

During the last 30 years, light rail transit (LRT) has overtaken heavy-rail rapid transit as the high-capacity, high-performance transit mode most often chosen for new urban transit corridors in the United States. Now one may find that bus rapid transit (BRT), typically with lower cost than light rail but similar capabilities, may overtake LRT as the mode of choice for corridors in which capital-intensive transit is justified. What is involved in deciding upon a best course of action? Are these "either-or" technologies, or simply different expressions of the same concept? The author argues in favor of the latter, and suggests a new term encompassing common forms of both modes, rapid light transit (RLT), LRT and BRT in terms of the functions to be served, the forms fulfilling those functions, similarities between BRT and LRT regarding those forms, and issues of cost, funding, and implementation are explored. It is noted that the BRT form of RLT is almost always the lower-cost alternative; a metropolitan area will be able to deploy a network of high-performance transit more extensively and quickly as BRT rather than as LRT. Also noted are reasons why LRT may be chosen despite its higher cost, but the potential for using BRT as a first step, with later conversion to LRT, is also discussed. An RLT facility might also share BRT and LRT vehicles, or even be converted from LRT to BRT―a simple transition if light rail has been built with tracks embedded in pavement suitable for BRT vehicles.