Research On The Left Out Of The Directional Ramp

The node in the urban road is the bottleneck of the whole road system, so if the traffic is not smooth, it will affect the traffic capacity and service level of the whole urban expressway system. A ramp spacing, exit ramp at weaving section, remind the channelization length and traffic facility location and set up a reasonable, conducive to reduce or eliminating the the of the road system bottleneck effects and safety issues and improve the traffic capacity and service level of the road system.Due to the current China, the vast majority of highway interchange exports were located in the right side of the main line, and therefore to be turning vehicles habits will be in the right lane driving, and when the exit on the left, prone to drivers hesitate, vehicle missed the exit, return, error, etc., resulting in traffic accidents; even consciousness to the outlet of the driver, also need to be within a short distance vehicle from running the right lane traverse to the left lane, to the sections of the straight flow brings large disturbance, an increase of accident probability.Firstly, this paper analyzes the traffic characteristics and the influence factors of the entrance of urban expressway.Secondly, the concept of traffic simulation is introduced in detail, the traffic simulation model, this paper introduces the classification of traffic simulation model, simulation model and the advantages and disadvantages of descriptor model. On the microscopic simulation is the most important two model of vehicle with following model and lane changing model are introduced. The simulation model calibration and verification, and the simulation experiment using the VISSIM software are introduced in brief.Next to the Beijing North Fourth Ring Road and Beichen Road intersection left out of the ramp as the investigation and research object, through the field observation, data collection and other methods to study traffic characteristics. From export geometric conditions, traffic impact and interweaving effect three aspects of several aspects, to export speed and the actual flow as the traffic index, respectively, of the various factors on export traffic impact; also in weaving speed as the index, analysis of the interlaced zone length for capacity of. Through the research, the influence of the length of the auxiliary lane, the change of the traffic flow and the length of the weaving area on the traffic capacity of the left exit ramp of urban expressway was analyzed.Then the study sections of the simulation, and the simulation results from the traffic characteristics, auxiliary lane geometry and traffic guidance measures set several aspects of qualitative and quantitative analysis.Finally, the research results are summarized, and the length of the deceleration lane and the traffic guidance facilities of the left exit ramp of Beichen East Road are put forward.