A Study on Appropriate Size of Urban Rail Transit Systems

Developing urban rail transit systems is an effective solution to traffic problems of big cities. The appropriate size of a rail transit system relates to the size, the economic level, and the land-use patterns of the city. There have been no domestic and oversea standards for referencing in determining the appropriate size of urban rail transit systems for cities with different sizes. Through a review of characteristics of urban rail transit systems, the GDP and population density of many cities in China and abroad, this paper develops a mathematical relationship between the appropriate size of an urban rail transit system and the population density of a city, which can be useful for urban rail transit systems planning.