基于改进分段截断二次速度轨迹模型的行程时间估计

Travel Time Estimation Based on Improved Piecewise Truncated Quadratic Speed Trajectory Model

为解决交通网络行程时间估计的问题,在经典分段截断二次速度轨迹模型的基础上进行改进,融入对速度变化的考虑,建立了改进的分段截断二次速度轨迹模型。首先,根据行程经过节点上游路段的累计时间窗来计算节点到达速度。其次,用各个路段节点到达时刻的速度代替出发时刻的速度。最后,用相邻三个路段节点的到达时刻速度构造速度轨迹,速度轨迹函数由拉格朗日二次插值基函数和常基函数构成。为验证改进模型的性能,引入经典分段截断二次速度轨迹模型作为对比,在实际道路上进行了实证研究。结果表明:改进的分段截断二次速度轨迹模型估计行程时间比原模型在均方误差和平均绝对百分比误差分别降低了46%和51%,且改进模型相对误差基本能保持10%以内,拟合度高于原始模型。

To solve the problem of traffic network travel time estimation,on the basis of classical piecewise truncated quadratic speed trajectory model,incorporating the consideration of velocity variation,an improved piecewise truncated quadratic speed trajectory model was constructed.Firstly,the node arrival speed through the cumulative time window of the upstream section node is calculated.Secondly,the velocity at the departure moment is replaced by the velocity at the arrival moment of each road section node.Finally,the arrival moment velocities of three adjacent roadway node is used to construct the velocity trajectories,which consists of a Lagrangian quadratic interpolation basis function and a constant basis function.To verify the performance of the improved model,the classical piecewise truncated quadratic speed trajectory model is introduced as a comparison,and an empirical study is conducted on the actual road.The results show that the estimated travel time of the improved segmented truncated quadratic velocity trajectory model is 46%and 51%lower than that of the original model in terms of mean square error and mean absolute percentage error,respectively,and the relative error of the improved model can be kept within 10%,and the fit is better than that of the original model.