我国经济建设中心逐步由沿海、经济发达地区向内地、西部边疆转移，而西部地区人烟稀少，经济欠发达，自然资源丰富，因此，西部干线铁路一般都具有设计年度内客货运量较小、有客货运作业的中间站少，而其路网意义重要、国家要求的输送能力较大等特点，按输送能力要求分布... China’s economic construction center has gradually shifted from the coastal and economically developed areas to the interior and western borderlands. However, the western region is sparsely populated, its economy is underdeveloped, and its natural resources are abundant. Therefore, the Western trunk railways generally have the advantages of less passenger and freight traffic during the design year, The middle of the operation is less, and its road network is important, the country requires more capacity and other characteristics of delivery, distribution capacity requirements distribution ...