Bottleneck Model Considering Variable Capacity

Nowadays,the problem of traffic congestion has become a stubborn disease of the city,and with the increase of car ownership in China,it is becoming more and more serious.Among them,morning and evening commuting peak period is the peak period of traffic congestion.Therefore,it is of great significance to study the commuting problem in the morning rush hour.In recent years,most of the research based on Vickery’s classical bottleneck model is only based on the further discussion under the condition of constant capacity.However,the traffic situation is complex,and the capacity at the bottleneck may change due to a variety of situations.Therefore,on the basis of variable capacity,this paper considers the harm of queue length to capacity,and further studies a continuous variable speed limit system to alleviate the problem.Firstly,based on the classical Vickery model,this thesis extends the case of single linear change and piecewise linear change for variable capacity.In view of these models,this paper makes a preliminary analysis and discussion,and obtains the equilibrium model of morning rush commuting.Secondly,due to the fact that the queue is too long in the actual traffic,it often causes a large area of traffic jams,which leads to the decline of traffic capacity.Therefore,this paper considers a variety of commuting models affected by queue length.In this model,when the queue length at the bottleneck reaches the threshold,the capacity will decrease immediately,and the capacity will not return to the original state after the decrease.In view of this situation,this thesis analyzes and discusses a variety of bottleneck models with variable capacity,equilibrium models after decline,and calculates and deduces the relevant time nodes and costs of these models.Thirdly,aiming at the problem of capacity decline,this thesis proposes a continuously variable speed limit system which can be applied in automatic driving environment.For various bottleneck models,this thesis calculates and derives the corresponding continuously variable speed limit system.The purpose of the system is to limit the speed of vehicles so as to avoid queuing at the bottleneck.On the one hand,it can avoid the decline of traffic capacity at the bottleneck and improve the traffic conditions,on the other hand,it can reduce the cost of harmful gas emissions.Finally,this thesis assumes several specific cases,calculates and verifies the accuracy of the model and the efficiency of the speed limit system according to the equilibrium model and the continuously variable speed limit system.Compared with the basic model,the model increases the commuting cost,commuting time and emission cost after the traffic capacity decreases.In addition,the overall commuting period also increases.After adding continuous variable speed limit system,compared with the model with reduced capacity,the individual commuting cost,total social commuting cost,total social commuting time and total social emission cost are reduced,and the overall commuting time is shortened.Compared with the model without capacity reduction,the system can also effectively reduce the total social emission cost.Figures 28;Tables 21;References 74...