我国现行的《公路工程技术标准》,二级公路的设计车连在平原微丘为80km/h1,线形要素的标准是较高的。但是,目前新建或改建二级公路,多是混合交通。由于近年来自行车、手扶拖拉机等慢行车日益增多,混杂度越来越大。每当高峰小时,行车秩序乱,事故多,车速慢,通过能力低。只有改为汽车专用公路。才能提高实际车速,充分发挥干线公路的效益。 China’s current “highway engineering standards”, two road design car even in the plain micro-mound 80km / h1, linear elements of the standard is higher. However, most of the newly-built or reconstructed secondary roads are mostly mixed traffic. Due to the increasing number of slow-moving vehicles such as bicycles and walking tractors in recent years, the degree of hybridization is getting bigger and bigger. Whenever the peak hours, chaos driving order, accidents, slow speed, low ability to pass. Only to the car highway. In order to improve the actual speed, give full play to the benefits of trunk highway.