Study On Impact Between Lane Changing Behavior And The Parameters Of Traffic Flow Characteristics In Weaving Area Of Urban Expressway

Lane changing behavior is a very common driving behavior. City expressway is located in city, lots entrance and has some characteristics of freeway. Many metropolis'expressway are reach saturated flow in daily peak hour, and keep the serve levels in level three to level four. On the roads, drivers often changing lanes for their desire, easily make traffic flow chaos and reduce road capacity. Unfit lane changing behavior is main reason for accident. At present the study of lane changing behavior focus on lane changing behavior, lane changing model and the relationship between lane changing behavior and single parameter of traffic flow. The relationship among lane changing behavior, speed and density is not involved. The research between the lane changing behaviors and traffic flow parameters most focus on freeways, some on normal roads and rarely in city expressway.Based on the surveys and literatures review, this paper had systematically study the lane changing behavior in city expressway. Sampled as the third round road in Chengdu, we were shooting the traffic flow in different lane style locations (4 points) in sunny days, then collected, organized and analyzed the data in room. We set up the relationship model with density, speed, the lane changing numbers of enter lane and the lane changing numbers of exit lane in different lane style locations and serve level three and level four on half. Aim to serve level three and serve level four on half,we got the parameter selection intervals of recommend formulas. Using the model, we compared with the density formulas (the relationship of "LWR"), and the recommend formulas fitting better than existing formulas. But the ending unity of different locations is not good as in different serve levels. Then we think that the relationship with density, speed, the lane changing numbers of enter lane and the lane changing numbers of exit lane is not concert with lane style and relevant with serve levels.In same lane using and different serve levels, I got good result in model. I think density has relationship not only with speed but also with lane changing numbers of enter lane and lane changing numbers of exit lane. The recommend formulas in this paper is a revise for exist density formulas.