Compared with traditional road transportation, subway has several advantages such as large carrying capacity, fast speed, and no pollution, making subway construction an effective method to alleviate urban traffic congestion. According to industry analysts, local governments in China have gradually included subway construction in their schedules, and the subway is expected to become the main investment target for urban transportation construction in the future.

The "Twelfth Five Year Plan for Comprehensive Transportation System" passed in March this year clearly requires the construction of a number of major railway projects, timely commencement of a number of urgently needed projects, and the initial formation of a comprehensive transportation network with "five vertical and five horizontal" as the main framework, with a total length of 4.9 million kilometers. According to the "Plan" goal, the operating mileage of the railway will increase to about 120000 kilometers, with the high-speed railway reaching over 40000 kilometers. The "Twelfth Five Year Plan" for the development of high-end equipment manufacturing industry, released in May this year, also clearly proposes to meet the needs of China's railway rapid passenger transportation network, large volume freight channels, and urban rail transit construction.　

On September 5th, the National Development and Reform Commission announced that 25 rail transit construction plans have been gradually approved. Among them, the recent construction plans for rail transit in six cities including Taiyuan, Lanzhou, Guangzhou, Shenyang, Xiamen, and Changzhou have been approved, while the recent construction plans for cities such as Harbin and Shanghai have been adjusted