1 引言我国西部地区10个省(市)区,面积545万平方公里,人口2.93亿, 2001年GDP1.45万亿元。公路运输是西部地区的主要运输方式。改革开放20多年来,公路基础设施有了很大进步,但仍是制约西部发展的主要因素,为适应我国西部大开发战略的要求,中央已明确提出加强西部地区交通基础设 1 Introduction China’s western region 10 provinces (cities) area, an area of ​​5450000 square kilometers, population 293 million, 2001 GDP 1.45 trillion yuan. Road transport is the main mode of transport in the western region. In the more than 20 years since the reform and opening up, the road infrastructure has made great strides, but it is still the major factor that restricts the development of the western region. In order to meet the requirements of the strategy for the large-scale development of the western region, the central authorities have explicitly proposed strengthening the transportation infrastructure in the western region