中文摘要：

针对城市道路混合交通问题，分析了小、中、大3类车型的车道、区位、断面分布特征，依据各车型车辆的道路路段固有阻抗和车型比例仿真构建了三幅路、四幅路、三幅路单行且公交可逆行等典型道路路段机动车流的车速流量实用模型（BPR模型），并以小、大型车比例差为变量对模型进行了修正．预测结果表明，修正模型能够适应各种交通组成情况，且具有相当高的计算精度，可以较准确地预测缺乏实地调查资料的道路路段交通流参数。

英文摘要：

Aiming at the mixed traffic on urban roads, an analysis was performed of the attributes of lanes, locations, and cross sections of small, medium, and large vehicles. Based on the intrinsic resistance and vehicle proportions of different traffic links, a link speed-flow model, i.e. the BPR model, was developed for simulating the vehicle traffic flow on the typical roads consisting of three-carriageway mad, four-carriageway road, and one-way three-carriageway road with a two- way-bus lane, respectively, and the model was modified with the variable of the difference between the proportions of small vehicles and large vehicles. The results of study demonstrate that the modified model is suitable for any mixed traffic condition and is of high accuracy; therefore it can predict the traffic flow parameters for traffic links in the absence of investigation data.