21世纪需要更为关注的环保问题,随着中国进入WTO,公路建设、养护也必将更注重经济的发展与生态环境的平衡,确保公路的可持续发展。据统计,目前全国高等级公路的里程约达20多万公里(高速公路约1.94万公里)。高等级公路一般均是交通干线,交通量大,养护工作多,养护费用高。为节省养护 In the 21st century, more attention needs to be paid to the issue of environmental protection. As China enters the WTO, highway construction and maintenance will also pay more attention to the balance between economic development and ecological environment and ensure the sustainable development of the highway. According to statistics, at present, the mileage of high-grade highways in the country is about 200,000 kilometers (about 19,400 kilometers of expressways). High-grade roads are generally traffic trunk, traffic, maintenance and more maintenance costs. To save maintenance