基于行程速度指数的城市快速路服务水平评价方法

根据城市快速路的特性, 将城市快速路分为基本路段、交织区和分合流区。运用Greenshields模型计算自由流行程速度, 通过双线圈检测器获取地点速度并由此估算行程速度。对行程速度指数进行右侧均值和均方差的一致性检验, 将服务水平量化, 提出了基于行程速度指数的城市快速路服务水平评价方法, 并在西安市南二环某路段上进行实例验证。评价结果表明: 当自由流、高峰时段、平峰时段的行程速度分别为82.514、47.825、67.930km·h^-1时, 高峰时段行程速度指数的均值和均方差检验结果分别为7.206、8.482, 城市快速路服务水平为2.667, 为Ⅲ级; 平峰时段行程速度指数的均值和均方差检验结果分别为6.408、8.960, 城市快速路服务水平为4.083, 为Ⅱ级。计算结果与实际情况相符, 提出的方法有效。

Evaluation method of urban expressway service level based on traveling speed index

According to the characteristics of urban expressway, urban expressway was divided into basic section, weaving section, diverging and merging section.The traveling speed of free flow was calculated by using Greenshields model, and spot speed data were collected through dual-loop detector to estimate traveling speed.After the consistency test of right side mean and mean square deviation for traveling speed index, the service level was quantified, the evaluation method of urban expressway service level based on traveling speed index was proposed, and example verification was carried out on the Southern Section of Second Circular Road of Xi'an City.Evaluation result shows that when the traveling speeds in free flow, peak period and flat peak period are 82.514, 47.825 and 67.930 km·h-1 respectively, the mean and mean square deviation of traveling speed index in peak period are 7.206, 8.482 respectively, and the service level of urban expressway is 2.667 and is Ⅲ level.The mean and mean square deviationof traveling speed index in flat peak period are 6.408, 8.960, and the service level of urban expressway is 4.083 and is Ⅱ level.The calculation result consists with actual situation, so the proposed method is effective.