Section 8: Suburban Railway in Urban Rail Transit:

The suburban railway, a unique mode of transport in urban rail transit, features longer routes and higher speeds than subways and light rails, catering to passengers traveling between suburbs and urban centers. Utilizing wheel-rail technology, it often intersects with conventional and high-speed passenger railways. Differentiated by service target rather than speed, the suburban railway connects urban and suburban areas, especially outer suburbs, often interconnected with conventional railways and sometimes sharing tracks. As cities expand, suburban railways extend beyond city-suburb borders, forming a rapid rail transit system centered on the city core, also known as urban express railways.

Suburban railways expand urban space, reduce city center population density, alleviate traffic congestion, and enhance urban living quality. They excel in facilitating passenger flow between megacities and satellite towns, integrating urban rail transit into a vast, convenient metropolitan transportation network that includes subways and light rails. Passengers can quickly reach their destinations within this network.

In the 1980s, major cities like Beijing, Tianjin, Shanghai, Nanjing, and Wuhan operated suburban railway trains, facilitating commuting. However, with the rise of highways, suburban railways lost ground due to their limited schedules, long intervals, and poor connections with urban transit. Like subways needing a network to thrive, suburban railways need seamless integration with other modes.

As cities grow and urban cores saturate, suburban railways have a new chance to develop passenger services. With low passenger volumes, they can operate with sparse schedules. Their main advantages include high transport capacity, fast speeds, low investment, quick returns, low costs (half of light rail and one-fifth of subway), and minimal environmental impact. In 2008, Beijing opened the S2 line from Beijing North Station to Yanqing, facilitating travel and access to attractions like the Badaling Great Wall. Beijing also plans five suburban railway lines in Mentougou, Miyun, Daxing, and Fangshan, forming a suburban railway network. Flexible construction can repurpose old, unused railways in urban hubs. New lines, like the Beijing-Tianjin Intercity Railway, are also necessary.