Research on Design of Expressway Acceleration Lane Length and Merging Model of Vehicle

In order to explore the influence of length of the acceleration lane on expressway traffic volume in main line and using the acceptance gap theory,running characteristics and capacities of the on-ramp merging region were analyzed.Based on the minimal acceptable headway,the probability of vehicles in the acceleration lane merged into the expressway was studied.According to the traffic volume and the minimal acceptable headway in the main line of expressway and acceleration lane,a new optimal design method of the acceleration lane length was presented,and the control model of the on-ramp traffic volume was obtained.The results show that if the method for recommending the acceleration lane length and the control model of on-ramp traffic volume are used,under the situation that the expressway traffic volume in main line doesn't change,compared with the traditional method,the traffic volume in on-ramp merging region is improved nearly double by the method.