Research on the Spatial-System-Based Rail Transit Systems of the World Cities

The urban rail transit system is the important basis to support the metropolitan regions of the world cities and has great significance to the formation and development of such metropolitan regions. From the perspective of relieving the urban traffic congestion, the development of rail transit requires multiple-levels and diversity; it's the key to accurately position the functions of the subway, the light rail, the suburban railway and even the national railway; then the functions should be integrated through the respective positioning and on the basis of the characteristics of different rail transit so as to give maximum play to the rail transit system. The paper dissected the basic composition, spatial layout, service objects, passenger flow scale and historical evolution of the rail transit system within the spatial system in the metropolitan regions of such world cities as Tokyo, London, New York and Paris. It compared and analyzed the main gap of Beijing's rail transit system and put forward the countermeasures and suggestions for the future development of rail transit.