Simulation-based Optimization Method For Arterial Coordinated Signal Control Considering Safety And Efficiency

The coordinated control of traffic signals in urban road network can effectively improve vehicle traffic conditions and alleviate traffic congestion.Intersections as critical nodes of the urban road network not only clearly impact the traffic efficiency but also have a high risk of traffic collisions.However,most studies on signal coordination control only pursue the improvement of traffic efficiency,but ignore the traffic safety.Therefore,this thesis proposes a simulation-based optimization method of arterial signal control with consideration of traffic efficiency and traffic safety at the same time.The main research results of this thesis are as follows.(1)This thesis establishes a bi-objective simulation-based arterial signal control model considering safety and efficiency simultaneously.In order to reflect the level of traffic safety in a more comprehensive way,with the help of traffic conflict technology,a surrogate traffic safety index based on vehicle speed,quality,and conflict type is designed as one of optimization objectives,while another objective,the traffic efficiency evaluation index,is the throughput.The optimization of signal control scheme involves phase sequence,signal cycle,green timing and offset.In order to adjust the signal phase flexibly,the ring-and-barrier structure of signal control is applied.(2)In order to solve the bi-objective simulation-based arterial signal control problem,a bi-objective surrogate-based promising area search(BOSPAS)algorithm is designed.In the BOSPAS method,the shrinking ball method is used to deal with the noise,and only one real evaluation is required for each candidate solution.This method greatly reduces the calculation time and saves the calculation cost.In the numerical experiments,BOSPAS is tested to outperform three other counterparts(i.e.,nondominated sorting genetic algorithm II(NSGA-II),bi-objective efficient global optimization(BOEGO),and bi-objective promising area search(BOPAS))by a stochastic FON function from the aspects of convergence and diversity.(3)In order to solve the simulation-based arterial signal control problem,a micro traffic simulation optimization platform is established by combining MATLAB,VISSIM and SSAM.Based on the simulation optimization platform,the bi-objective surrogate-based promising area search is used to signal control optimization of real road networks.Meanwhile,this simulation optimization method is compared with Synchro software,MAXBAND and MULTIBAND.In addition,in order to test performances of signal control plans obtained under different performance indexes,the traffic efficiency is evaluated by the throughput of the arterial road and the road network,respectively.