Legal analysis: railway grades are divided into three levels: the first-class railway plays a backbone role in the railway network, and the second-class railway plays a backbone or liaison and auxiliary role in the railway network with a long-term annual passenger and freight volume of 20 Mt or more, and the long-term annual passenger and freight volume is more than or equal to 10 Mt and less than 20 mt; The third-class railway serves a certain area and has the nature of regional transportation. The long-term annual passenger and freight volume is less than 10 Mt, and the annual freight volume is in the direction of heavy vehicles. Each pair of passenger trains on single-track railway is 1.0 Mt, and the annual freight volume on double-track railway is 2.0 mt. ..

Legal basis: People's Republic of China (PRC) Railway Law.

Article 2 Railways mentioned in this Law include national railways, local railways, special railways and special railway lines. National Railway refers to the railway managed by the competent department of the State Council Railway. Local railways refer to railways managed by local people's governments. Special railway refers to the railway managed by an enterprise or other unit and providing transportation services for the enterprise or unit. Special railway lines refer to the branch lines managed by enterprises or other units and connected with national railways or other railway lines.

Article 3 The competent railway authorities in the State Council shall be in charge of the national railway work, implement a highly centralized and unified transportation management system for the national railways, and provide guidance, coordination, supervision and assistance to local railways, special railways and special railway lines. National railway transport enterprises exercise management functions entrusted by laws and administrative regulations.