Research On Optimization Model For Transit Priority Of Urban Road Signal Intersection Group

The routes of buses are complex and the frequency of departure is high in urban road signal intersection group.The short distances between each intersection and the high saturation lead to the limitation of available bus priority space and time resources.There exists the disequilibrium of demand and supply between social vehicles and buses,buses and buses,intersections and intersections.By researching the method of bus priority control of urban road intersection group,the relationship between the traffic demand of public traffic vehicles,the traffic demand of social vehicles and the space supply capacity in the intersections can be balanced,the efficiency of road network can be improved and the negative impact on social vehicle can be reduced.This paper analyzes the cause of short-lane effect and invalid bus travel time,the coupling mechanism of bus control and intersection group,and also overall consider the change of the traffic flow,spatial,topological and signal timing characteristics.Basic static data and operation data of social vehicles and buses in the intersection group are acquired by using artificial investigation,bayonet electronic police,RFID(Radio Frequency Identification)detector and GPS(Global Positioning System)detector.And the raw data is then filtrated and cleaned.Moreover,this paper collects the data of the arrival time distribution,speed distribution and travel time distribution of buses,the distance between intersections and bus stations,and traffic flow saturation,and analyzes the relationships between each of them,which lays a foundation for the follow-up researches of bus priority multiple application sort allocation model and signal timing optimization model.The optimization objective,control structure,functional structure and priority control process of bus priority control strategy for urban road signal intersection group are carried out.To guarantee the realization of bus priority control strategy for urban road signal intersection group,this study constructs hierarchical distributed logic structure of regional road network layer,intersection group layers,bus main path and intersection layer;constructs a functional structure for intersection group includes application layer,transmission layer and perception layer.It also designs the impact analysis module for short lane effect on bus operation of intersection group,multi-application sort allocation module for bus priority of intersection group,signal timing optimization module for bus priority of intersection group and other key modules.The intersection group with bus lane outermost are analyzed,includes how the layout form of the entrance for bus lane and the location of bus stations impact on the bus operation in the intersection group.Spatiotemporal trajectory map is used to analyze the qualitative impacts of bus delays in multiple short lane scenarios such as mixed lane,bus lane,the entrance of bus lane and bus station.The corresponding bus delay improvement model is given for quantitative analysis.Finally,general model of total vehicle delay for intersection group and bus signal priority strategy are carried out to coordinate the design process.The method and process of multi-application optimization control for intersection group are put forward in this paper.The state of operation of all buses at intersection group is identified by using multi-steps detectors includes RFID,GPS and bayonet electronic police.Bus route priority level is calculated and bus main route is identified by defining the bus delay-saturation index.Considering the interactive effect of the saturation of upstream and downstream intersections and the number of bus applications,the 0-1 mixed integer bus priority control model is constructed under the minimum vehicle delay on objective function.The dynamic programming method is adopted to prioritize the application of the bus signal priority multi-application sorting model,and the assumptions,objective function and solution process are given.In this paper,we contrast the adaptability of the bus prioritization control method,the single-point bus prioritization control method and the bus priority control method based on the bus route priority,respectively.The methods in this paper is more suitable for optimal control of bus priority in intersection group with high saturation and complex bus routes.The principle of timing control of bus priority signal,the process of the timing and the bus signal priority strategy are put forward in this paper.Aiming at the invalid bus priority time existing in the multi-phase bus signal application,historical data is used to make an offline signal optimization program,and the signal control parameters are adjusted online based on multi-step check-in-checkout.Based on the Ring-Barrier structure,the model formula of extended green and early green is proposed.The ring-barrier structure is used to construct the model formula of green light extension and green light start ahead of time in a single period,the dual-loop phase sequence model considering two cycles,and the signal control response the principle of multi-step check-in-check-out,and the fuzzy theory is adopted to solve the priority control model of single bus signal.The improved learning algorithm based on interactive coordination is used to realize the real-time adjustment of the bus signal control parameters between adjacent intersections in the intersection group.With the increase of stop time and traffic saturation,bus can still show mature effect,but the optimization effect begins to decrease.If the bus priority measures such as bus lanes are used alone in a section of the intersection group,the delay of social vehicles will increase,and the total delay will increase at a single point.The signal timing optimization method proposed in the paper is suitable for the priority control of bus signals at intersections with many bus lines and strong bus operation volatility.