Studies On Timing Optimization Of Signalized Intersection Of Historic District

In recent years,with the rapid development of urbanization,the traffic problem gradually caused wide public concern in historic district.Especially the space of historic district is narrow,the number of slow traffic is large and the situation of the mixed traffic of motor vehicles and non-motor vehicles is serious,which make intersection become the “bottleneck” of traffic flow.Optimizing the signal timing of intersection can improve the efficiency of the operation of the intersection effectively.But most of the signal timing of intersection in historic district is based on the motor traffic flow,and without taking into full consideration to the needs of crossing the street of slow traffic.Therefore,this paper studies giving a priority to slow traffic in signal timing optimized is necessary in historic district.Firstly,this paper conducted a field survey about intersection of historic districts where were showed in the planning of Xi'an,investigated the geometry characters,the signal timing and the traffic flow characteristics of historic district,analyzed the rule of arrival and release of pedestrians,non-motor vehicles and motor vehicle in the intersections,also build a model about the crossing time of slow traffic and raised the improvement measures and some advices based on giving a priority to slow traffic in the intersections of historic district.Secondly,the most methods of signal timing in the intersection which given a priority to motor vehicles was contrasted in this paper.And a model of giving a priority to slow traffic in signal timing optimized design of historic district was proposed,which was established with minimum delay of slow traffic,minimum interference of crossing time and maximum numbers through the intersection as the objective function.To improve the subject status of the slow traffic,to give a priority to guarantee demands of the slow traffic,to make the traffic in the intersection efficiency,low-carbon,orderly in historic district.Again,the benefit of the motor vehicles was taken into account on the basis of the signal timing plan of slow traffic priority in the intersection of historic district,and a bi-level programming model which considered slow traffic and vehicle traffic in signal timing was proposed.Considering the slow traffic demand in the intersection of historic district as the planning target of upper control,the delay and stops of vehicle as the lower-level control.And implementing comprehensive optimization design of signal timing with pedestrians,non-motor vehicles and motor vehicle by using the Gauss-Seidel method to solve the model.Finally,taking intersection of Houzaimen-Beixinjie of historic district in Xi'an as an example.And applying the mode of the signal timing of slow traffic priority to optimize the signal timing of the period,the number of slow traffic is larger and the number of motor vehicle traffic is small.Using the mode of the slow traffic priority which considering motor vehicles to optimize the signal timing of the peak period in this intersection,the number of slow traffic and motor vehicle traffic are both larger.To calculate the model results and compare the indices such as delay,stops of traffic flow with the status quo and gain the ideal results.To test and verify the rationality and applicability of the presented scheme of giving a priority to slow traffic.