基于移动检测数据的宏观基本图特征

为了实时检测和评价城市交通网络的拥堵态势，发掘城市网络交通流的内在特性，构建基于移动检测数据的交通网络宏观基本图（MFD），分析MFD的特征和变化规律.在移动车辆渗透率非均匀分布的条件下，结合固定检测器数据，利用可变渗透率对MFD进行估计.以杭州市为例，利用7 109辆出租车的GPS轨迹数据，研究交通网络MFD特征.结果表明，提出的分段取平均值作为该区间扩展系数的计算方法，相较于直接采用平均值作为整体统一扩展系数的计算方法，能够更加有效地应用于城市道路网络的实时交通状态监测.
Abstract: An approach to reconstruct the macroscopic fundamental diagram (MFD) was proposed based on probe data in order to detect and evaluate the congestion of urban traffic network in real time, and analyze the inherent characteristic of urban traffic flow on road network. The characteristics and variation patterns of MFD were analyzed. Given the non-homogeneous distribution of probe penetration rates, procedures were presented to magnify MFD variables with varying penetration rates estimated by the GPS data combined with the fixed detections. The accuracy and the characteristic of MFD were tested with trajectories of 7 109 taxis in Hangzhou, China. An estimation method of expansion coefficients was presented for the MFD reconstruction, using piecewise mean according to the ranges of the flow rate and density, respectively. The method generates a more accurate MFD that can be useful to inform real-time traffic monitoring required to implement control strategies in the field compared with the historical mean as the uniform expansion coefficient.