曾几何时，国人谈起全封闭的高速公路，绝大多数都还感到迷们而不知是何物。然而，弹指一挥的十余年间，国人对高速公路就不再觉得神秘了，高速公路已遍布全国各地。汽车跑决了，更显得火车跑得太慢。尽管每年10亿人次的客运量、20亿吨的货运量把全国57800公里的铁路压得喘不过 Once upon a time, people talk about the fully enclosed highway, the vast majority still feel lost and I do not know what it is. However, in more than a decade, the Chinese people no longer feel mysterious about the expressway. The expressways have spread all over the country. Run the car, it seems that the train ran too slowly. Despite the passenger traffic of 1 billion passengers each year, 2 billion tons of freight will push the 57,800 km of railways across the country