Research On The Optimization Strategy For Signal Timing On Urban Arterial Roadway

The benign development of transportation system has a strong relationship to the sustainable development of cities and human beings.While in the most of the big cities,with the development of the social economy,living standard,automobile industry,and infrastructure construction,the number of vehicles are increasing rapidly,which induces the traffic congestion that makes the vehicle travel time longer,rises the frequency of road rage,pollutes the environment.With the development of computer technology,system theory,control theory,and many other advanced information technologies,some new methods that improving the utilization rate of existing traffic resources to ease the traffic congestion are more popular to be used.As a basic unit in the traffic system,single intersection should be researched firstly,which plays a foundational role in the researches on whole transportation system.Therefore,if ones want to optimize the whole traffic system,it is important and necessary that researching how to optimize the signal timing at an isolated intersection.So,how to construct an accurate and effective optimization model for urban traffic system has a profound theoretical and practical significance of managing the urban transportation system.In this dissertation,discussing around the urban traffic signal,two major contents have been researched:I)signal timing for a signalized isolated intersection based on multi-objective optimization algorithms,which gives some necessary support to research on the signal coordination optimization on urban arterial roadways;2)according to the researches on the signal timing for single intersection,the signal coordination optimization on urban arterial roadways based on multi-objective optimization algorithms has been discussed.The main tasks and innovation points are as follows:(1)In this dissertation,some theories of quantum computing are introduced into the multi-objective genetic algorithm.Thus,a new multi-objective genetic algorithm is proposed,which is applied to optimize the signal timing for a single intersection.In Chapter 3,according to the multimode and randomness of quantum,initializing the initial population with quantum code to make the initial population random purely;then,evolving the populations by using the concept of quantum rotation gate.Thus,a non-dominated sorting quantum genetic algorithm(NSQGA)is proposed,then using the proposed algorithm to optimize the signal timing at a certain intersection.The research method and approach provide a reference for the research on the signal coordination optimization on the arterial roadway.(2)In this dissertation,on account of the identifying for traffic condition on arterial roadways,a two-level fuzzy identification model for recognizing the traffic condition on the urban arterial roadway is proposed.In this two-level model,the whole identification process is divided into two stages:in the first stage(called low level),using fuzzy comprehensive evaluation(FCE)and fuzzy analytical hierarchy process(FAHP)to identify the traffic condition in both directions on the arterial roadway,respectively;in the second stage(called high level),integrating the resulting identifications obtained from low level by applying fuzzy logic and fuzzy rules,then,it is not hard to get the most proper coordination strategy for signal timing on the arterial roadway.By applying this technique,the coordination system can alter the control mode automatically,according to the corresponding traffic condition,to increase the utilization of resources,decrease the cost,raise the efficiency of operation and management of urban traffic system.At the end of chapter 4,an assumed urban arterial roadway composed of three identical signalized intersections is selected to finish the simulation experiment.And,use the output from VISSIM as the input to the proposed model,comparing the resulting identification and the video on the VISSIM,it is shows that the precision and effectiveness of the proposed model have a satisfying performance,which means this model can provide some reliable decision makings for traffic managers and researchers.(3)In this dissertation,an operational-feature based multi-objective optimization coordination model for urban arterial roadway is constructed,where the vehicular factor(average vehicle delay and average queue length)and environmental factor(exhaust emission)are both taken into consideration.Furthermore,in terms of average vehicle delay,a new analytical delay model based on the graphical method is proposed,which is used in this study.And then,assuming an ideal urban arterial roadway composed of three intersections,the signal timing along the arterial roadway is optimized by two frequently used arterial coordination optimization models and the new proposed model on MATLAB.And,the proposed model is solved by a multi-objective genetic algorithm.After the optimization process,the optimal results obtained by the three models mentioned above are input to VISSIM to make horizontal comparisons.The simulation results present that the proposed model can give consideration to both major road and minor road,simultaneously,and,make the traffic system more environmentally friendly.In addition,the new model can deal with such a traffic condition better that the traffic flow on the arterial roadway is unbalanced in both directions.