Segmented Signal Priority Models For Urban Modern Streetcar Based On Stations

Guided by the national promotion of modern streetcar planning and construction, modern streetcar is show up prominently and vigorously in the urban traffic. The original incentive of the study is that there is a lack of systemic signal priority methodologies and technologies to ensure modern streetcar’s high efficiency in its ascendant development. The work was sponsored by the National Key Basic Research and Development Play 973 (2012CB725402) and the National High Technology Research and Development Program 863 (SS2014AA110303). The thesis is developed in four aspects:the method of segmented signal progression for modern streetcar between stations, the real-time signal priority for modern streetcar under low saturated intersection, the real-time signal priority for modern streetcar under high saturated intersection, and the capacity analysis of the intersection under modern streetcar signal priority. More specifically, this study is divided into the following contents.(1) In the first place, the traffic signal timing methodology at an intersection with the modern streetcar is renovated, by the introduction of the minimum green time model, the effective green time model and clearing time for modern streetcar phase. And this traffic signal timing methodology serves as the basis for the study on modern streetcar coordinated signal control. In the next place, the method of segmented signal progression for modern streetcar between stations is proposed and acts as the fixed-time signal priority for modern streetcar. The model is structured based on the buffer time margins cooperative optimization of the uplink and downlink modern streetcar arrival time at intersection. It takes into consideration the modern streetcar travel time constraints from passenger service time at station, charging time, running time on the road, cycle time and effective green time of the modern streetcar phase.(2) A real-time signal priority methods in view of moern streetcar efficiency optimization is proposed, which is applied at intersectons with small traffic flow. The methods is based on the segmented signal progression of modern streetcar. The rock-bottom constraint of non-modern streetcar phases is determined by the requirements of normal at-ground traffic safe driving, pedestrian and bicycle crossing at the intersection. The prediction model of modern streetcar arrival time at intersection is proposed based on theLayout of detection device. The signal cycle is divided into six subintervals, according to modern streetcar arrival states. The real-time green time model for each subinterval is structured, coorespondingly.(3) Another real-time signal priority methods in view of non-modern streetcar phase stable operation is proposed, which is applied at intersectons with heavy traffic flow. The methods is also based on the segmented signal progression of modern streetcar. The rock-bottom constraint of non-modern streetcar phases is determined by dissipation time of the normal at-ground traffic vehicle-queue. The normal at-ground traffic vehicle-queue dissipation time model is structured based on the control objective of non-secondary stop at the intersection. The signal cycle is divided into four subintervals, according to modern streetcar arrival states. And then, the real- time green time model for each subinterval is structured.(4) The capacity analysis method of the intersection under modern streetcar signal priority is proposed, by the revising stopping line method in the respects of control-datum plane, average headway and formulas of green time. Firstly, capacities of the intersections under the segmented signal progression of modern streetcar are analyzed, based on intersections with before-and-after data of modern streetcar construct about the signal phase, phase sequence, intersection channelization, traffic organization and average headway from Shenyang City. Secondly, the related data is collected from intersections of Nanjing City. The distribution probability of real-time green time for each phase methods is obtained by Vissim simulation under the two real-time signal priority. The capacities are analyzed and compared that belong to intersections under different modern streetcar signal priority strategies.