Rapid Rail Transit (Metro) System. Implementation and Expansion Technical and Operational Challenges Review - The D.C. Metrorail Case Study

Abstract The Rapid Rail Transit (Metro) systems have been set as an important tool for world cities to supply the transit riders (users) the mobility and accessibility requirements in the high demand (highly loaded) urban corridors, which require a combination of large passenger capacity and service quality. Given their large capacity and the associated high service level and environmental performance, the metro systems provide a high quality accessibility, which ultimately, set them as a structural tool to drive the long term urban spatial and economic development. Metro systems are set as urban megaprojects, given their required very large outlays of capital intensive investments on long-lived assets, such as guideways, stations, rolling stock, and the associated systems (electrification and signaling). The system’s design features might strongly affect its capacity, operational flexibility, service performance, and cost, with the passenger-carrying capacity in the highest-demand sections of the network being one of the most critical design parameters, given its effect on the system’s investments. This work presents, based on the state of the art available public technical data, a review of the rail metro technology challenges associated with their implementation and expansion initiatives. To do so, it reports the Washington D.C. (District of Columbia) Metrorail experience, at the United States (U.S.), an iconic metro system, which has been successfully planned in the sixties and implemented in the, which has revolutionized the greater Washington Metropolitan Area mobility and urban planning and that currently is set among the busiest metro systems in the U.S. Nevertheless, despite its groundbreaking transit performance, it currently faces both refurbishment (rehabilitation) and expansion demands, whose diagnosis and proposed solutions are reported in this paper to illustrate the metro rail challenges to provide the required adequate transit service throughout its service life.