损失车头时距与几何构型对城市快速路匝道合流区瓶颈效应的影响机理

城市快速路在缓解拥堵上起到了重要作用，但其匝道合流区往往成为通行瓶颈；前期研究发现该位置车辆合流导致大量换道行为，对瓶颈形成有明显影响，其中车头时距是一重要参数，部分值域的车头时距因无法充分用于换道被“损失”掉，而匝道合流区的几何构型则通过约束车辆运动空间影响该位置的瓶颈程度；但如何量化集计“损失”的车头时距，匝道合流区的几何构型以及不同驾驶员在合流中的行为特征对瓶颈效应有何影响尚不明晰。据此提出采用损失车头时距来研究一定几何构型下匝道合流区瓶颈效应程度。拟基于交通流理论，结合交通流数据分析与微观仿真技术，采用数学建模的方法，就损失车头时距与几何构型对匝道合流区瓶颈效应的影响机理进行研究，探索瓶颈处交通流状态演化的复杂性和多变性问题，阐明匝道合流区瓶颈效应的内在形成机理并量化不同交通条件下的“瓶颈度”，为通过有效的交通设计和驾驶员行为干预提高城市快速路匝道合流区交通运行水平提供参考。

Urban expressway played an important role to solve growing urban traffic congestion, but its on-ramp junction always become the capacity bottleneck position of the urban expressway’s. Previous study found that lane change behavior caused by vehicle merge lead to significant impact on the formation of bottleneck effect’s, this is where headway has played an important impact on the lane change behavior, part of the range of headway was loss because of not fully used for lane changing, and geometric construction of on-ramp junction influence its degree of bottleneck effect through constrained vehicle’s movement space. But it is still unclear about how to quantify and aggregate the "loss" headway, and what are the effects of geometric construction and the driver behavior characteristics in merging to bottleneck effect. Then put forward using the headway-loss to study degree of bottleneck effect of urban expressway on-ramp junction on the basis of a certain geometric construction. Intend to according to the traffic flow theory, and combination of data analysis and microscopic simulation, using the method of mathematical modeling, study on influence mechanism of headway-loss and geometric construction to bottleneck effect of urban expressway on-ramp junction, explore the complexity and variability of the evolution of traffic flow states at the bottleneck, its important to clarify intrinsic formation mechanism of bottleneck effect and quantify the degree of bottleneck under different conditions of urban expressway on-ramp junction, establish the theoretical foundation about through adoption of effective traffic design and driver behavior intervention to improve the traffic operation level of the urban expressway on-ramp junction.