Empirical Analysis of the Speed Synchronization of Merging Vehicle from the Entrance Ramp

摘要

Exploring the lane change preparation, termed as synchronization, with a new integratedview may trigger the understanding of the complex lane change behavior and helpmicroscopic traffic flow modeling. This paper reports a fundamental work from variousaspects to study the speed synchronization behavior of the merging vehicle by tracking theirtrajectories on the merge-related lanes. By classifying the merging vehicles into “OriginalGap” type and “Overtaking” type, the existence of the speed synchronization during the lanechange preparation stage is proved by comparing the speed difference between the mergingvehicle and PL (putative leader) /PF(putative follower) at different locations. After this, asynchronization rule of the merging vehicles is constructed. The merging vehicles tend tomaintain a speed which is 5~7 m/s higher than the speed of PL to overtake unsatisfiedcurrent gap on the adjacent main lane. When they meet an acceptable gap, they would take atwo-step strategy to merge into main lane. Then, the effect of the speed difference betweenmerge vehicles and PL/PF on the gap selection are concluded, which is that higher speeddifference leads to gap rejection. Finally, the absolute speed difference between mergingvehicle and PL/PF are modeled using multi-regression method. The number of rejected gapsby merging vehicles, the merging vehicles' speed synchronization direction (acceleration ordeceleration), the speed difference between PL and PF, the time headways, the distance frommerging vehicles’ current location to the end of the auxiliary lane and the vehicle type of PLof merging vehicles are found to have significant effects on the speed difference tolerance.