Study On Optimization Of Pedestrian Signal For Two-stage Crossing With Minimum Delay

In recent years,with the acceleration of urbanization process,the scale of road network is expanding,and the design level of intersections is increasing.Meanwhile,the development of motorization has caused more and more pressure on road facilities.Traffic accident has become a common problem.In order to bear the function of transportation for different kinds of traffic flow and guarantee the safety of pedestrians,two-stage crossing is taken into consideration.The change of signal phase has changed the perception of traffic safety.However,the traditional signal optimization method of two-stage crossing synchronizes vehicular phase with pedestrian phase and has not defined the specific position of pedestrian traffic in urban road network system.Therefore,under the background of two-stage crossing at isolated intersection,assuming undersaturated traffic condition,signal optimization method combined with traffic efficiency of pedestrian traffic and vehicular traffic is studied to provide support and basis for formulating traffic management plan,so as to give full play to the guiding role of traffic in urban development.In order to propose a signal optimization method of two-stage crossing to meet the needs of urbanization development,the relationship between the traffic indicators and traffic efficiency is established in this paper.Firstly,the characteristics of classification of two-stage crossing and refuge island are analyzed,and the macro and micro parameters of the pedestrian traffic,as well as demand of time and space,are summarized.Secondly,on the basis of in-depth analysis of phase design of two-stage crossing at four-phase intersection,according to the intersection indicators and pedestrian traffic indicators and vehicular traffic indicators,the traffic efficiency index system of two-stage crossing is built,and the traffic efficiency index system and signal timing parameters are conbined by delay to build the signal optimization model of two-stage crossing with minimum delay at isolated intersection based on the traffic efficiency index system,aiming at reducing the average delay of pedestrians and vehicles as much as possible.Then,the method of investigation and processing of traffic data is studied.Finally,taking Huju South Road-Hanzhong Road intersection in Nanjing as an example,applied research is conducted according to the model in this paper.The pedestrian traffic indicators and vehicular traffic indicators are taken into account in the signal optimization method of two-stage crossing in this paper,which can be used to provide reference for setting signal phase in the stage of planning and design at new intersection,and the same to provide basis for formulating traffic management plan in the stage of maintenance and transformation at exiting intersection.The signal optimization model of two-stage crossing with minimum delay at isolated intersection proposed in this paper is tested by VISSIM,and the results show that the delay of pedestrians is reduced 10.81% and the delay of vehicles is reduced 7.94%.Therefore,the model can effectively measure the traffic operation state of all kinds of traffic flow at isolated intersection,which can provide the basis for signal optimization.