四、高速公路的横断面设计高速公路的横断面,主要包括行车带、中央带和路肩三个组成部分(图1),现分述如下: (一)行车带从理论上说高速公路所需的车道数,应根据远景设计年(一般取20年)较繁密方向、高峰小时混合交通换算所得的小汽车数量和每一车道每小时所能通过的小汽车辆数(日本取为6,000～14,000辆)通过计算求得,但 Sectional Design of Expressway The cross-section of expressway mainly includes the three components of driving belt, central belt and shoulder (Figure 1). The following are described as follows: 1. Driving belt In theory, Of the number of lanes should be based on the number of cars converted from mixed traffic in the more prospective design years (generally 20 years), peak hour traffic hours and the number of vehicles per hour each lane can pass (Japan takes 6,000 to 14,000 By calculation, but