Lane-change frequencies in freeway traffic flow.

Using data taken from aerial photography of freeway traffic, the author studied lane-change on multilane freeway sites near off-ramps under various levels of flow. As expected, the greatest frequency of lane-changes is to the right for exiting vehicles, and increased frequency of lane-changes to the left by through vehicles that moved back to the right near the off-ramp where exiting vehicles leave the freeway. A discussion of the theoretical and practical implications is included.