Research On Delay Models At Signalized Intersections Based On The Traffic Simulation Of VISSIM

The city road intersection is the bottleneck of the traffic capacity and trafficsafety in the whole network. If there is overpass exit, tunnel exit in keep in lane areaupstream the stop line, or the roadside bus lane exist, in order to avoid the interlacedtraffic upstream the stop line, two detached left-turning lanes are put into use in someintersections in many Chinese cities. As a general rule, inside and outside left-turningtraffic in the same direction share a same green phase. So they rejected each other andlead to the increase of traffic delay.After analyze the traffic operating characteristics and traffic delay of signalcontrol intersections, this paper simulate a living example of road intersection withtwo detached left-turning lanes by VISSIM traffic simulation system. Revise theparameters of traffic flow for the purpose of guarantee the reliability of trafficsimulation precision, in order to analyze the inside left-turning traffic delay whichcaused by outside left-turning traffic. In the operation of VISSIM traffic simulation,take the traffic flow parameters include traffic volume, traffic composition, thedistance between inside and outside left-turning lanes and the turn over volume of theinside left-turning lane as constants while the corresponding parameters of the lateralleft-turning lane as variables, then get the discrete data in VISSIM after operation.Process these data with linear regression and get inside left-turning delay influencefactors model. At last, propose the reasonable traffic facilities improvement byoptimize the signal phases and install the U-turn paths based on the simulationresearch results. Compare the delay of inside left-turning and the whole intersection ateach cycle that before improvement with which after improvement. The conclusionproved that the facilities improvement is effective. So it has the actual meaning ofguidance for other the same type of intersection improvement.