市郊铁路一般是指站间距一般在1公里以上和5公里以下,运行速度一般在120km/h或者更高,主要服务于城市郊区化和同城化发展趋势的、具有公交化和通勤化特征的轨道交通线路,属于城市轨道交通的一种形式。从发达国家的发展历程来看,市郊铁路是支撑都市圈、城市带发展的基础,也是 Suburban railways generally refer to orbits with the characteristics of public transportation and commuting, which mainly serve the suburbanization and urbanization trends of urban areas, where the station spacing is generally over 1 km and below 5 km, and the operating speed is generally 120 km / h or higher. Traffic lines, belonging to a form of urban rail transit. From the perspective of the development of developed countries, the suburban railway is the basis for supporting the development of metropolitan areas and urban belts.