雾天环境下高速公路可变限速控制方法研究

针对雾天环境下高速公路能见度下降导致交通安全和效率降低的问题,提出了一套雾天环境下高速公路的可变限速(VSL)控制方法,包括系统布置、工作流程和可变限速控制策略等,可以根据检测到的实时道路能见度和交通流数据,考虑最大安全车速、交通流运行状态和驾驶员遵从度等因素的条件下,综合确定目标路段的限速值.利用G4高速公路实测数据,在Vissim软件中进行了2组对比仿真实验,结果表明,与无可变限速控制相比,实施可变限速控制的1组,最低车速在平流雾(团雾)环境下提高了27.24%(28.54%),同一控制周期下相邻路段的最大车速差减少了26.42%(41.91%).提出的可变限速控制方法在雾天环境下能更有效地保障高速公路行车的安全和效率. 

A Traffic Control Method for Freeways Using Variable Speed Limits under Foggy Weather

Fog leads to a decline of visibility on freeways,which decreases safety and efficiency of traffic.A variable speed limit(VSL)control scheme for freeways under foggy weather conditions is proposed,including system design, workflow,and VSL operation strategy,etc.The speed limit of target sections is determined based on data of real-time road visibility and traffic flow,factors including the maximum safe speed,traffic state and non-compliance behaviors of drivers,etc are considered.Data collected from the G4 freeway and simulations are analyzed by Vissim.The results show that compared with no control scheme,the proposed scheme can increase the lowest speed in advection(agglomerate)fog by 27.24%(28.54%)and decrease the maximum speed difference of adjacent link by 26.42%(41.91%).This VSL control scheme is more effective in agglomerate.Furthermore,it ensures traffic safety and improves efficiency of freeways in foggy weather.