Methodology For Spatial-temporal Resources Allocation Of An Arterial Road With Variable Approach Lanes

With the accelerated process of urbanization and the soar of population and vehicles in China,traffic congestion has become a focused problem in our life.While there are so many reasons which induce traffic congestion,a variety of solution methods occur continuously.Some congestion problems which caused by uneven distribution of traffic flow at different periods can be solved by setting a variable approach lane.Therefore,how to simultaneously optimize the control of variable approach lanes and the signal timing schemes has become an important project.Abandoning previous studies which optimize cycle length,green split and offset in turn,and considering the influence of variable approach lanes and short lanes,on the basis of HCM2000 vehicle delay model,models for spatial-temporal resources allocation of an arterial road with variable approach lanes are set up,which utilize minimizing the total delay of the arterial intersections as the objective function,and the offset,the function of variable approach lanes and the effective green time as decision variables.To guarantee the smoothly operation of vehicles during the transition of control schemes,the computational method of the adjusted switch points for control schemes and the control method for variable approach lanes are designed,all the achievements are to proposed the entirely control method for variable approach lanes.To systematically describe the models and methods,this thesis is divided into five chapters.The first chapter analyzes and summarizes the research background,research significance,and the domestic and overseas research status,furthermore,introduces the objectives,contents and methods of this research.The second chapter elaborates the establish process of the optimization model,including the improvement of the vehicle delay model,the establishment of the spatial-temporal resource optimization model,the general applicability analysis of the model and the proposal of the control method of variable approach.In the third and the fourth chapters,an isolated intersection and three consecutive intersections are separately considered into models.Optimized schemes are obtained by utilizing the mathematical software MATLAB,actual road networks are simulated by using the traffic simulation software VISSIM,and signal timing schemes are edited by exploiting the signal control logic tool VisVAP.The effectiveness of the optimized models and the proposed methods can be verified by comparing and analyzing the operation effect under the control of the optimized and current schemes.The fifth chapter summarizes the thesis and shows future prospect.The results show that the optimized model for spatial-temporal resources allocation of an arterial road is universal and reliably.The optimized model is not only suitable for arterial intersections,but also isolated intersection or paired intersections;it can not only consider the setting of variable approach lanes,but also short lanes.For the full time period,the function of variable approach lane and signal timing schemes which are designed by the model can minimize the total delay and queue length for all the intersections.For different periods,different intersections,different flows,the optimized models can enhance the operation effect of most of the research objects,additionally,the proposed control method of variable approach lanes can guarantee the smoothly transit of signal timing schemes and the safety of traffic flow operation during the transition periods.Therefore,the methodology for spatial-temporal resources allocation of an arterial road can not only design the signal timing parameters of isolated intersection and arterial intersections,plan the function of variable approach lanes effectively,but also can ensure the smoothly operation of vehicles,all the achievements are to provide some references and basis for alleviating urban traffic congestion.