高速公路长大上坡路段的通行能力及安全分析方法

Analysis Method of Traffic Capacity and Safety of Long and Steep Upgrade Sections in Expressway

在实测数据的基础上,以VISSIM为仿真平台,建立长大上坡路段仿真模型,分别以交通量、大车混入率、坡度、坡长为参数对长上坡路段的通行能力和车辆运行安全进行仿真试验。仿真结果显示:通行能力随着交通量的增加先增加,至道路饱和状态后,开始减少;随大车混入率的增加,通行能力呈下降趋势;通行能力随着道路坡度的增加明显呈下降趋势;坡长对通行能力的影响与坡度密切相关。冲突率作为长上坡路段交通安全评价指标,随着交通量的增加呈先增加后降低的趋势;随着大车混入率增加,冲突率先增加后减少,混入率为40%时交通冲突率达到峰值;随着坡度和坡长的增加,交通冲突率呈上升趋势,并且增长率越来越大。

Based on the measured data and VISSIM simulation platform, the simulation model of long and steep upgrade section was established. The simulation experiments for traffic capacity and safety on long and steep upgrade in terms of traffic volume, large vehicle proportion, slope and slope length were conducted respectively. The simulation results show that （ 1 ） traffic capacity increases with the rise of traffic volume at first, when road getting saturated, traffic capacity begin to decrease, and it decreases with the increase of large vehicle proportion and road grade; （2） the effect of slope length on traffic capacity is closely related to slope grade ; （3） as a traffic safety evaluation index for long upgrade road section, conflict rate increases with the rise of traffic volume at first and then decreases, and conflict rate increases with the rise of large vehicle proportion at first and then decreases, which reaches peak value when large vehicle proportion becomes 40% ; （4） conflict rate increases with the rise of slope grade and length with enhanced growth rate.