Study On Traffic Flow Model And Numerical Calculation Method

The traffic problem has become the shackles to the development of our society, it’s notonly the hot topic between people, but also the focus of the society, and clear, safe, healthytraffic environment has become the measure of a civilized and harmonious city’s importantsymbol. From the last century30’s, the whole world experts and scholars study the trafficproblem has more than80years, in the different historical period traffic problems reflectdifferent shape, this also force traffic engineering researcher pay more attention to study itsvarious new situation and the new features.Nowadays, the rapid boom of economic,also the rapid development of society, and theincreasingly improved of automotive technology, making motor vehicle quantities intoprogression growth in recent years, in the train of The traffic problem present a rowdy faces,traffic jam has let everybody take for granted, vehicle exhaust has let us have no alternative,and facing lots of Shocking traffic accidents we still can’t away from the sufferer, trafficproblem has serious influenced on our normal life, also serious obstacle to the healthydevelopment of the society, We traffic engineering researchers have the responsibility alsohave the obligation to made unremitting exploration the traffic problem in the new period.This paper makes use of computer numerical simulation technology to analysis andresearch traffic flow problem, on the basis of predecessors’ study establish microscopictraffic flow model, then use finite difference method discrete model, establish the multilanetraffic flow model of microscopic simulation, and develop corresponding simulationplatform with C language in Linux system environment, This paper mainly studies how toestablish the urban traffic flow microscopic simulation model, and write simulation programon this basis, it made some achievements, basically have:(1) Analysis and research at home and abroad the main results of theoretical studies oftraffic flow and microscopic traffic flow model, draw inspiration from the finite elementmethod, the road is divided into a tiny limited unit. These units are divided into two kinds of state, active and inactive, when there is a vehicle above on the unit, the unit is active, andotherwise it is inactive. The finite element method is analysis and calculates the stress-straininteractions between all adjacent cells, while its application to traffic flows theoretically,only analyze of the active unit, based on this idea establish suitable for finite elementdiscretization of multi-lane traffic flow model.(2)Design and write the discrete multi-lane traffic flow model simulation programwhich based on finite element method, it including the establishment of the road model, thedivision of the road grid, the processing of road and vehicle information data, vehiclegeneration, following traveling between vehicles, free traveling, change lane traveling,across signalized intersections, Visualization of the results of data and so on.(3)Traffic survey outside，then make some of the survey data as a result of inputconditions, which is equivalent to the set of boundary conditions, then calculate under theconditions of simulation, the calculation of the output compared with the actual trafficflow to analysis, from the point of view of the traffic volume analysis to verify theeffectiveness and stability of the simulation system.(4)Take advantage of simulation systems to analysis some factors affecting roadcongestion, in particular, some not facilitate experimental testing factors, such as thedistance between the adjacent intersections have some influence to intersection congestion.The results show that: in the case of constant arrival rate of vehicles, the longer the distancebetween the adjacent intersections, the queue length will be more longer; When the smallerdistance between the adjacent intersection (e.g.250m,500m), then the queue length of thevehicle road share will rise soon. Other easily lead to traffic congestion factors for example,the arrival rate of vehicles surged or signal design unreasonable, will lead to between theadjacent intersections of the section packed with vehicles, more serious consequences iscause the behind intersection loss its hub function, resulting in the paralysis of the roadnetwork. Finally, take some my own thinking about the traffic flow problems in the futureresearch and development; further illustrate the focus of future research and developmentdirection.