Macroscopic Characteristics of Lane-changing Traffic

On a multi-lane roadway, systematic lane-changes can seriously disrupt traffic flow and cause capacity reductions. Therefore it is important to understand the characteristics of lanechanging traffic flow. In our previous study, a new variable, lane-changing intensity, was theoretically derived by doubling the contribution to the total density of a lane-changing vehicle during its lane-changing period, and a intensity-density relation was incorporated into the fundamental diagram to capture such bottleneck effects at the aggregate level. In this study, we propose a new interpretation of lane-changing intensity by following Edie’s definition of traffic density. We then present our detailed studies of macroscopic characteristics of lane-changing traffic with 75 minutes of vehicle trajectories collected for a freeway section on interstate 80 by the NGSim project. Here we are able to exclude about 10% misindentified lane-changes. For different time intervals, cell sizes, and locations, we further verify the well-definedness of the lane-changing intensity variable and intensity-density relation. Future directions are discussed in the conclusion section.