基于修正通行能力的道路出入口位置优化方法

Optimization Method of Road Access Location Based on Modified Capacity

作为城市道路路段上的典型接入点,出入口的数量是影响道路通行能力的重要因素。首先分析了出入口干扰对路段通行能力的影响,将出入口数量因素采用最外侧车道出入口物理修正系数进行表征,出入口处车辆的驶入和驶出产生的减速跟驰、变换车道等影响采用横向折减系数进行表征,并进而提出了综合修正系数,构建了考虑出入口干扰的路段通行能力半解析计算模型。其次,结合出入口与交叉口的距离、出入口间距等约束条件,以修正后的通行能力之和最大为目标函数,提出了出入口位置优化方法。最后以郑州市某居住区为例进行了方法验证和实例应用。计算结果表明,为使居住区周边道路的通行能力之和最大,出入口应优先设置于等级较低的城市道路路段中点处;随着出入口数量的增加,出入口接入道路应由低等级道路向高等级道路依次选择;当城市道路等级相同时,应优先选择车道数较少的道路。

Access point was important part of urban road sections.The number of entrances and exits was a main influencing factor on urban road capacity.Firstly,the influence of entrances and exits on capacity of a road section was analyzed.Effects caused by the number of entrances and exits was represented by the physical modification coefficient of entrances and exits on the outermost lane.Speed reduction and lane changing effects caused by the entering and exiting of vehicles on entrances and exits were represented by the transverse reduction coefficient.Furthermore,the comprehensive modification factor was proposed.Considering influences of entrances and exits,a calculating model of road section capacity was constructed.Secondly,taking into account the distance between access points and intersections,access spacing constraints,using the maximum sum of modified capacities as the objective function,an optimization method for access location was proposed.Finally,a residential area in Zhengzhou city was taken as an example to testify the feasibility.Results showed that in order to maximize the sum of modified capacities of roads around the residential area,accesses should be preferentially set in the middle of low-grade urban road sections.With the number of access increasing,the access roads should be selected from low-grade roads to high-grade roads in sequence.When road grades were same,priority should be given to roads with fewer lanes.