Analysis And Research On The Impact Of Buses On Road Traffic Flow

Obtaining the rules and mechanisms of urban transportation systems is the basis for alleviating the problem of urban road congestion.Urban traffic is a typical complex system.The interaction between various traffic flows and people flow on the road makes it difficult to find rules in the traffic system.Especially with the rapid development of urban public transportation,such as the setting of urban rapid transit and harbor-type bus stations makes bus traffic affect each other.It is found that the law has a certain meaning for the planning of the urban transportation system road network,designing the bus network and dispatching bus operation.The cellular automaton is an important method to solve the above problems.Therefore,the cellular automata theory was adopted to study the impact of buses on road traffic flow.A traffic flow cellular automaton simulation model containing bus stop sections was established.The model consists of two parts: the basic element definition and the running rule.The basic elements of the model include vehicles,road and bus stops.Considering that the vehicles in the city are mainly cars and buses,therefore,these two vehicle models are only considered,and this two vehicles are represented by different numbers of cellular;Considering the relevance of the vehicle’s operating status to the location of the bus stop.In order to facilitate the analysis of the problem without loss of generality,the entire road section is divided into three lanes and five sections,then;Considering that the bus stations in the city mainly include two types of harbor and non-port type,so only the two bus stops are discussed in the model.Vehicle operating rules include normal vehicle driving rules,vehicle lane changing rules,and bus stop rules.The NS model(random cellular automaton traffic model)is adopted for normal vehicle driving rules;In view of the influence of the speed of the vehicle,the speed of the preceding vehicle,the distance between the vehicle and the preceding vehicle and the driving state of the adjacent lane,then,car lane change rules were proposed;Bus lane change is affected by the demand of the pit stop,the rules for the basic change of the bus,the change of the lane with a given probability,and the forced change of the lane are given.In order to obtain effective model parameters,the initial values of the parameters are obtained through data analysis and field investigation.The proportional relationship of the vehicle is obtained through analysing the vehicle type detection data in the microwave flow data;The vehicle parking time range is obtained through analysing bus GPS data;The data of selecting the parking space for buses is obtained through manual collectionat at field bus stops.In order to analyze the impact of buses on road traffic flow,a traffic flow cellular automaton simulation model was established.The number of bus stops and the bus stop time were analyzed,and the law of the influence on traffic flow was obtained.