城市快速路匝道最小间距模型

Models for determining minimum distance of ramps on urban expressway

匝道间距是路线设计中的重要内容,对交通流有决定性的影响。根据城市快速匝道的特点,应用驾驶员行为理论,模拟了驾驶员城市快速匝道上的驾驶行为。认为匝道间距是影响城市快速路主线运行状况的关键因素。为了合理确定匝道最小间距,必须确定匝道组合模式和计算匝道加减速车道长度,并计算出车流从匝道汇入主线后,由于车流变道而形成交织车流长度。由此建立了不同匝道组合模式下的匝道最小间距模型。应用实例表明,当匝道间距不能满足最小间距时,车速降低,服务水平下降。

The distance of ramps is the key for designning road route, it has a big effect on the mainline traffic flow of urban expressway. According to the ramps features of urban expressway, the driving at the ramps of urban expressway was simulated with drivers behavior theory. In order to determine the minimum distance of ramps the lane lengthes for acceleration and deceleration were calculated under different ramp structures, and the calculating formulas were given. The model for determining the minimum distance of ramps was developed. An example shows that when the distance of ramps is less than the minimum distance, the vehicle's speed will be cut down, the service level of ramps will be reduced.