城市快速路期望车头间距模型的建立

Study on Expected Headway Model in Urban Expressway

通过对跟驰车队刺激-反应过程以及人车单元组合的微观特性分析,说明了跟驰车队中具有产生混沌现象的必要特征．首先运用数学方法给出了4种期望车头间距理想模型,将Rossler混沌吸引子模型分别引入这4种模型中,然后选择能更好地描述实际交通流状态的期望车头间距模型,并利用高精度车载GPS设备在城市快速路上采集的实测跟车数据对该模型进行标定和验证后,改进的期望车头间距模型能更好地反映实际交通流的跟驰特性．

A quantitative analysis is conducted on the chaos phenomenon in the car-following fleet based on the headway kept by the two consecutive vehicles and the follow-up vehicle＇s speed. By studying the microscopic characteristics of the vehicles fleet in the process of stimuli and reaction, it is proved that there exists a chaos occurrence in the car-following fleet. In order to reasonably model the expected headway in traffic stream, four expected desired headway models are proposed. Then, the Rossler chaos attractors are introduced in those four models to choose the models that can describe the actual traffic characteristics. The calibration and validation procedures are conducted using high accurate GPS equipped vehicles to collect data from expressways. Based on the results it can be seen that the modified headway models can best reflect the car-following characteristics of the real traffic flow.