????????????С???????????????????о???

在实施公交优先政策时，往往因没有对公交专用道和社会车道所应分担的交通量做出正确的估算而造成道路资源的浪费，以至于无法真正实现公交优先的目的.本文以公交车与社会车辆的行程速度差异为研究对象，通过分析设置公交专用道后两种交通方式间的转移情况，在保证公交车服务水平的前提下基于路阻函数研究了不同公交车比例下公交车和社会车辆的行程速度曲线，并确立了小汽车向公交车的转移关系.研究结果表明，针对不同的居民出行量及模型参数值，公交车在一定的比例范围内时小汽车用户选择公交出行，并使道路交通系统达到最优.该模型可应用于城市现有道路改造时公交专用道设置及确定公交车发车间隔的参考依据.

Modeling Modal Shift of Car Travelers to Buses Based on Public Transport Priority

For the implementation of public transport priority,the deviation on estimating traffic flow assignment to bus lane and general lanes may lead to the waste of road space resource,consequently fail to achieve the goal of public transport priority.In this paper,the differences between travel speed of buses and cars and modal shift relationship are explored.A travel speed curve of bus and car speed variation under various bus proportion is obtained based on road impedance function.The result shows that in accordance with distinct passenger trip volumes and modal parameter values,there is an appropriate range of bus.Within this range,car travelers are willing to shift to buses,and road traffic system can be optimized as well.The proposed model serves the installation of bus lane on existing urban roads together with determining the bus dispatch interval.