The Research On Variable Speed Limits Control Of Expressway Based On Enhanced CTM

The Chinese Academy of Engineering considered the severe urban traffic congestion as the first symptom of urban morbidity.With the development of cities,the demand for motor vehicles is increasing rapidly,and a series of traffic problems on urban expressways need to be solved urgently.The traditional speed limit control application has some limitations,and it cannot give a scientific and reasonable speed limit according to the real-time traffic flow condition and the real-time environmental change.The variable speed limit control provides a new method to solve the above problems.It detects the real-time traffic flow state through the traffic flow detector and calculates the current optimal speed limit according to the variable speed limit control strategy.It improves the traffic condition of the expressway by intervening the main traffic flow of the expressway.Variable speed limit control,as one of the important means of expressway traffic control,has been widely concerned by scholars in recent years and has achieved certain results in practical application.The results of previous studies show that the key problem of variable speed limit control still needs further study.This paper is helpful to further improve the basic theory of variable speed limit control and lay a foundation for the follow-up research.From the aspect of practical application,the development of the paper is helpful to improve the level of domestic expressway control and improve the expressway traffic operation.Firstly,this paper summarizes the previous research on variable speed limit control from different perspectives and sorts out the relevant progress and defects of the existing research.Secondly,the data of real traffic flow under variable speed limit control is analyzed,and the influence of variable speed limit control on traffic flow is summarized.It is found that the variable speed limit control cannot improve the traffic capacity of the control section,and the variable speed limit control can control the inflow rate of the bottleneck area and prevent the traffic capacity from decreasing,so as to improve the traffic efficiency of the expressway.,combed the cell transmission model is applied to the original variable speed-limit control of traffic flow simulation,based on the cell transmission model is established under variable speed-limit control of traffic flow simulation model,then the traffic flow simulation model parameters calibration and model validation,model validation results,said the paper set up simulation model of traffic flow under the variable speed-limit control of the error is around 7.8%,compared with the original transmission model of cellular automata have improved significantly.Finally,based on the feedback control system,a variable speed limit control strategy is designed to improve the efficiency of the expressway.The results show that the variable speed limit strategy proposed in this paper can effectively solve the problem of traffic congestion.After the implementation of variable speed limit control,the total travel time of vehicles in the road section is reduced by 27.6%,and the traffic efficiency of the expressway is significantly improved compared with that in the case of no control.