关键词: 交通工程, 时空传播特征, 时空自回归模型, 连续合流瓶颈, 三相交通流

Abstract: To reveal the spatiotemporal propagation characteristics of traffic phase transitions and their key influencing factors at consecutive merge bottlenecks, this paper selected the Zouhuang Interchange in Wuhan as the study site, and conducted research by the high-precision trajectory data under congestion intensification and congestion mitigation scenarios collected via unmanned aerial vehicle. The stages of congested traffic flow were first identified by three-phase traffic theory combined with changepoint detection, after which the congestion propagation speed was used to determine the slope of spatiotemporal units. Microscopic trajectories were then aggregated into explanatory variables; the wide moving jam proportion was constructed as the dependent variable, and a spatiotemporal weight matrix incorporating bottleneck constraints was designed; a spatiotemporal autoregressive model was established to estimate the spatial spillover effects of phase transitions under both scenarios and to conduct scenario simulations. Results show that neglecting bottleneck constraints causes the spatial spillover coefficient to exceed the reasonable range. After incorporating the constraints, the spatial spillover effects are opposite in the direction between two scenarios: significantly negative during congestion intensification (−0.655) and significantly positive during congestion mitigation (0.947). Scenario simulations indicate that the priority deployment zone for variable speed limit measures is the 300~540 meters downstream section from bottlenecks, and the key location for lane-changing control is the upstream merge bottleneck. Early intervention at the upstream on-ramp is recommended, while downstream on-ramp control becomes more effective after congestion has sufficiently propagated upstream.

Key words: traffic engineering, spatiotemporal propagation characteristics, spatiotemporal autoregressive model, consecutive merge bottlenecks, three-phase traffic theory