考虑通行能力和交通流稳定性的雾天高速公路限速研究

Speed-limiting strategy considering traffic capacity and stability of foggy freeway

从通行能力和交通流稳定性两个层面对雾天高速公路限速值进行研究。选取经驾驶模拟器数据标定的雾天跟驰模型来描述车辆跟驰行为,并计算雾天高速公路通行能力和交通流稳定性。分别提出优先考虑通行能力和优先考虑交通流稳定性的雾天高速公路限速方案。研究结果表明:轻雾场景和浓雾场景分别在限速100 km/h和80 km/h时的通行能力最大,均在限速40 km/h时的通行能力最小;轻雾场景和浓雾场景均在限速40 km/h时的交通流稳定性最优,分别在限速60 km/h和100 km/h时的交通流稳定性最差;采用优先考虑通行能力的限速方案时,雾天高速公路通行能力最大,较最小通行能力可提升28.68%~44.66%,稳定性则较最优值下降18.81%~82.92%;采用优先考虑交通流稳定性的限速方案时,交通流稳定性最优,较最差值可增加1.97倍~106.33倍,通行能力则较最大值减小22.29%~30.87%。

The speed-limiting strategy of foggy freeway was studied from two aspects:traffic capacity and traffic flow stability.Firstly,a car-following model calibrated by driving simulator data was selected to describe the following behaviors of vehicles in foggy weather,and the traffic capacity and traffic flow stability of freeways with different fog densities were calculated.Then different speed-limiting schemes of foggy freeway were proposed,which give priority to traffic capacity and traffic flow stability respectively.The results show that,the traffic capacity in light fog and thick fog scenarios is the maximum at the speed limits of 100 km/h and 80 km/h respectively,and the minimum at the speed limit of 40 km/h.The traffic flow stability is the best at the speed limit of 40 km/h,and the worst at the speed limit of 60 km/h and 100 km/h in light fog and heavy fog scenarios,respectively.When the speed limit that prioritizes traffic capacity is adopted,the traffic capacity of foggy freeway is the maximum,which increases by 28.68%~44.66%compared with the minimum value,but the stability decreases by 18.81%~82.92%compared with the optimal value.When the speed limit giving priority to the stability of traffic flow is adopted,the traffic stability is the best and increased by 1.97~106.33 times compared with the worst,but the traffic capacity is reduced by 22.29%~30.87%compared with the maximum value.