Modelling And Simulation Of Intersection Group Speed Guidance Based On Moving Block In Connected Vehicle Environment

In recent years,the time delay,security risk and air pollution caused by traffic congestion have seriously constrained urban development.The economic losses caused by traffic congestion account is equivalent to 5%to 8%of gross domestic product(GDP).The intersection is the main distribution point of urban road network traffic flow,more than 80%of traffic delays are concentrated at intersections and road bottlenecks.Therefore,the management and control of intersection group has become one of the most effective solutiorn to urban traffic congestion.The development of Connected Vehicle(CV)has realized the information sharing between vehicles,roads and signal lights,which can guide multiple vehicles pass through intersection group effectively.And one of the key issues in CV environment speed guidance is driving safety in efficient traffic.The moving block theory focuses on maximizing railway operation efficiency through minimizing vehicle tracking intervals,to obtain a balanced,safe and precise speed guidance.Therefore,research on intersection group speed guidance based on moving block theory is of great significance to solve urban traffic congestion problem.This paper studies on the multi-lane intersection group network in CV environment,and a speed guidance model is established based on the moving block theory,to ensure the efficiency and security during vehicles passing through intersection group.Firstly,the research status is summarized in four parts:the speed guidance in traditional traffic environment,the speed guidance in CV environment,the speed guidance of intersection group and the moving block theory,and the research content and technical route of this paper are proposed.Secondly,with a brief introduction of CV,paper compares and analyzes typical speed guidance model in traditional urban road system environment and CV environment,then advantages and disadvantages of different models are summarized.Thirdly,the moving block theory and its applicability in speed guidance is analyzed,the concept of time window is introduced to convert signal green time to practical block time interval,thus the single-point speed guidance strategy and collaborative speed guidance strategy of intersection group is built considering guiding principles,guiding logic and guidance model design etc.elements.Fourthly,multiple CV environment simulation scenarios are constructed based on EstiNet simulation software and secondary development,which realizes the information sharing of vehicle to vehicle and vehicle to infrastructure,and single-point and collaborative speed guidance strategies are developed in CV environment simulation scenarios.Fifthly,a synthetic evaluation function(SEF)of speed guidance in CV environment is proposed combining efficiency(Idle Time,Delay Time,Average Speed),security(Acceleration Rate),pollution(Polluting Emission)and reliability(Travel Time Reliability)indexes to measure performance differences with or without speed guidance,and 6 indexes'variation trend is analyzed though the comparation between different speed guidance models,like single-point and collaborative models,single-point and classic models,fixed block collaborative and moving block collaborative models.Finally,sensitivity analysis of Penetration rate(PR),compliance rate(CR),communication distance(CD),and guidance environment(GE)is performed in allusion to the proposed models'simulation performance.The simulation results show that the value of SEF is increased form 0.003 to 0.160 after the implementation of single-point speed guidance model,while seven indexes of PE,IP,DT,AS,AI and TTR are improved by 11.3%,93.5%,63.1%,14.0%,22.2%and 38.8%.The result of independent-samples T test shows that the collaborative speed guidance model can further enhance the average speed compared to single-point speed guidance model.The comparation between different models shows that single-point speed guidance model obtains a greater improvement on IT and TTR compared to classic speed guidance model,and the collaborative speed guidance model based on moving block obtains higher AS and TTR than the model based on fixed block.The sensitivity factor analysis shows that the speed guidance performance improves with the increase of device PR,CR and CD,and when the values of PR and CR are above 50%,the improvement rate of the models increases distinctly,as CR presents a higher SEF value with equal CR and PR,In addition,the speed guidance model based on moving block has a better performance in suburban environment compared to urban environment.