Models And Simulation Of Traffic Flow Research Considering Operation Of Bus Rapid Transit

With the rapid development of urban economy, the continuous rising of resident income and living condition, the ownership of vehicles increase greatly and the urban traffic grows fast. The serious urban traffic congestion and air pollution problems have become the bottleneck restricting the development of urban economy. It is well known that the bus rapid transit system is a kind of effective international engineering means to solve the problem of urban traffic, and it has been accepted and promoted widely as a public transport mode. It can bring many opportunities to solve the problem of city traffic.Based on the existing classical traffic flow models through overall analysis, combining with the characteristics of the urban mixed traffic, considering the special motor vehicle type, large bus rapid transit vehicles in the traffic flow, this paper calibrated the cell length, running speed and acceleration rules, put forward the lane-changing rules, established several models about BRT, finished the simulation by MATLAB software, and validated the model through the case study.Specific work included the following contents:(1) Firstly, this paper analyzed the characteristics of the BRT, summarized the component of bus rapid transit, and pointed out its advantages.(2) Secondly, this paper analyzed the car-following behavior, obtained the accelerated speed according to the nonlinear theory of stimulus-response, and improved the NS model by introducing the parameters such as average distance headway and space occupancy. The simulation of the improved model was fulfilled with the MATLAB software. In the free flow phase, road traffic flow was not affected by the length of the vehicle. In the blocking phase, the BRT was more likely to have a local blockage than a car at the same density, the propagation speed of the blockage in the rear is also faster and probability of the occurrence of stop-and-go is higher. At the same condition of lane occupancy ratio, the length of the vehicle was shorter, the traffic route would be greater, but the speed decreased rapidly. Therefore, in actual traffic, different sections developed differentiated operating rules.(3) Thirdly, this paper joined the lane changing rules, constructed multiple lanes traffic flow model with a bus-only lane, got the space-time diagrams and lane occupancy ratio variation diagram under two kinds of traffic management measures, then this paper analyzed the two kinds of effects on the traffic flow. In the actual traffic, traffic flow is different in different periods, we should develop some feasible operational measures to improve the utilization rate of the lane, reduce congestion and emissions, and improve environmental conditions.(4) This paper gathered the actual traffic flow data by Beijing BRT line 1. Using the method of statistical distribution, this paper concluded that the arrival distribution of private cars and ordinary buses was the binomial distribution, the arrival distribution of bus rapid transit arrival was poisson distribution. On this basis, model of traffic simulation was used to analyze the traffic characteristic.