What are the similarities and differences between urban rail transit and ordinary rail transit in terms of track?

According to international standards, urban rail transit trains are divided into three types: A, B and C, which correspond to train widths of 3m, 2.8m and 2.6m respectively. All rail transit lines using A-type or B-type trains are called subways, and 5-8 trains are used. The rail transit line with C-type trains is called light rail, and 2 ~ 4 trains are used. Vehicle type and train formation determine the axle load and platform length. Shanghai Rail Transit Line 3 uses six A-type trains, 90% of which are on viaducts, but it still belongs to subway lines according to the vehicle classification standard. Shanghai Rail Transit Line 6 adopts four C-type trains, 70% of which are in tunnels, but it still belongs to light rail lines according to vehicle classification standards. Type A train is the highest-end urban rail transit train at present. Its characteristics are wide car body and large grouping. The width of Type A train is 3 meters, and the width of Alstom Metroplis subway train used in Shanghai Rail Transit 10 line reaches 3.2 meters. The maximum passenger capacity of 6 A-type subway trains is 2,460, and the maximum passenger capacity of 8 A-type subway trains of Shanghai Rail Transit 1 Line and Line 2, Alstom and Siemens is 3,280. The cost and technical content of B-type and C-type cars are less than that of A-type cars.

With the development of China, some large and medium-sized cities have opened or are building subways and light rails. Ordinary people have little contact with the urban rail transit system and understand it relatively late, so there are some misunderstandings in their concepts. For the difference between the two, some people think that in urban rail transit, the subway is called the subway, and the light rail is the ground or overhead light rail; Others think that the rail weight of light rail is lighter than that of subway, both of which are wrong. Urban rail transit can be divided into subway and light rail, and can be built underground, above ground or on elevated roads. In order to enhance the stability of the track, reduce the workload of maintenance and repair, increase the backflow section and reduce stray current, both the subway and the light rail choose the international standard double track with the track gauge of 1435 mm as the train track, which is the same as the track specification selected by the national railway train, and there is no so-called track weight difference.

Subway is not limited to the form of running lines in underground tunnels, but generally refers to a high-standard electric passenger train and a large-capacity urban rail transit system with a one-way transportation capacity of 25,000 to 70,000 people during peak hours. The running lines are diversified, and underground, ground and elevated are organically combined. Many cities at home and abroad have replaced the traditional name "subway" with "rail transit". For example, Shanghai named the urban rail transit system "Rail Transit Line XX".