高架出口匝道下游交叉口信号控制方法研究

城市高架快速路与地面道路，主要通过出口匝道及其下游交叉口进行交通转换，高峰时段出口匝道及下游交叉口交通拥堵频发。以元胞传输模型为基础，构建出口匝道及下游交叉口交通预测模型；采用动态调整周期时长和信号相位的控制策略，建立基于元胞传输模型的交叉口信号控制模型。以排队长度、绿灯和周期时长为约束条件，以各进口道加权平均延误为目标函数，进行信号配时动态优化。以成都市实例匝道和交叉口进行验证，表明本文提出信号控制策略可有效降低此类交叉口的饱和度、延误和排队长度，提升其通行效率。

Study on Control Method of Signal at Intersection of Elevated Off-ramp Downstream

The traffic between urban elevated expressways and surface roads mainly transforms through off-ramps and downstream intersections. The traffic congestion occurs frequently at off-ramps and downstream intersections during peak hours. Based on the cellular transport model, a prediction model for the traffic of off-ramp and downstream intersection is built. The intersection signal control model based on cell transmission model is established by adopting the control strategy of dynamically adjusting the cycle length and signal phase. The dynamic optimization of signal time is carried out by taking the queue length, green light and cycle time as the constraints and the weighted average delay of each entrance as the objective function. The example of ramps and intersections in Chengdu is verified, which shows that the signal control strategy proposed can effectively reduce the saturation, delay and queue length of such intersections, and improve the traffic efficiency.