包含出入口匝道的高速公路路段行程时间估计方法

Travel Time Estimation on a Freeway with Ramps

针对高速公路路段是否包含出入口匝道的特征,提出了1种行程时间估计改进方法。根据不同类型路段流量变化及影响范围,通过匝道物理位置对传统半距离法中路段行程时间的取值进行优化,获得了适应于匝道引起流量不均衡的行程时间估计方法。以南京机场高速公路为背景,通过Vissim仿真所得地点速度值,结合路段行程时间真实值,检验所提方法的性能。实验结果表明:当路段出入匝道的流量均衡时,所提方法较半距离法的精度提高3.71%,较空间线性插值法精度提高4.59%,当出入匝道的流量相差较大时,所提方法较半距离法的精度提高16.27%,较空间线性插值法精度提高17.29%。结果验证了改进方法较半距离法和空间线性插值法更具优越性。

An improved method of travel time estimation on a freeway with focusing on the freeway section charac‐teristics is proposed .In consideration of traffic flow fluctuation and influence areas on different sections ,the proposed method optimizes the estimates of the travel time on freeway sections based on the locations of ramps on the link and it is applicable for the freeway sections with ramps which cause an uneven traffic flow .The proposed method was tested on Nanjing Airport Highway as a case study by simulated speed from Vissim and the actual travel time .The results show that the accuracy of travel time estimates could increase 3 .71% and 4 .59% comparing to the estimates by semi‐distance method and space linear interpolation method respectively when the traffic flow rates of ramps were balanced ;the accura‐cy of travel time estimates could increase 16 .27% and 17 .29% respectively when the traffic flow rates on ramps were sig‐nificant different .The results confirmed that the proposed method could provide more accurate travel time estimates on freeways .