Study On Setting Conditions And Main Technical Indexes Of Auxiliary Lanes For Composite Interchanges

The rapid development of China’s economy,the rapid expansion of the road network,the increasing density of the road network,the number of interchanges,and the distance between corresponding adjacent interchanges are also decreasing.When the distance between two adjacent interchanges is reduced to a certain extent,it needs to be set as a composite interchange,and this article is to study the connection of two adjacent interchanges into a composite interchange by setting auxiliary lanes.The factors affecting the composition and setting of auxiliary lanes in compound interchanges are studied.Classify the compound interchange connection methods,analyze the advantages and disadvantages of each connection method,and propose the composition of the compound interchange auxiliary lanes,including the entrance section,the interweaving section and the exit section,and the three influencing factors of the setting,namely the length of the compound interchange intersection,Traffic volume and traffic signs.For the study of the setting conditions of the compound interchange auxiliary lanes,first define the compound interchange intersection area,and calculate the length of the compound interchange intersection area based on the theory of the intersection area according to the HCM2000 method.The minimum length of the compound interchange intersection area based on the lane change theory is calculated,and the minimum length of the compound interchange intersection area is obtained by combining the above two results.The minimum length of the compound interchange intersection area is added to the length of the auxiliary lane acceleration and deceleration lanes,and finally the minimum length of the compound interchange auxiliary lane is obtained,and the setting conditions of the compound interchange auxiliary lane are proposed.Then,a simulation experiment was conducted to determine the form of the auxiliary ramp exit ramp of the composite overpass,the factors affecting the acceleration lane and deceleration lane length of the auxiliary lane were analyzed,and the calculation model of the acceleration lane and deceleration lane length was proposed.Based on the actual measurement results of the confluence area,mathematical statistical methods were used to study the driving characteristic parameters of the vehicle flow in the sub-confluence area and the confluence area.At the same time,according to factors such as design service level and traffic capacity,the cross-section technical indicators of the compound interchange hub are determined.Finally,the VISSIM simulation experiment was used to verify and analyze the applicability of the auxiliary lane of the compound interchange and the correctness of the auxiliary lane setting conditions.