CHONGQING -- Chongqing in Southwest China had more than 400 km of urban rail transit in operation by the end of January, according to the municipal commission of housing and urban-rural development.

Metro and intercity railways are the two main modes of public transport in the mountainous city. The municipality's first rail line opened in June 2004 by Chongqing Rail Transit (CRT).

The first phase of CRT Line 9 officially opened on Jan. 25. With a total length of about 32.3 km and 26 stops, the first phase of Line 9 links the city's central areas. Hongyancun Station is about 116 meters underground, making it the deepest station in Chongqing.

"The newly opened line connects the city's important business and port areas, which will greatly improve travel for commuters and support the economic development of the downtown area," said Ma Lingfeng, an official with the commission.

Several new lines will open in Chongqing in 2022, and the mileage of the city's rail transit both in operation and under construction is expected to exceed 850 km by yearend, said Ma.