Locations and Length of Entrances and Exits of an Automated Truck Lane on a U.S. Freeway

Abstract

Automated Truck Lanes (ATLs) are most likely to be constructed in the median of a highway. Among the important design considerations of an ATL are the locations and lengths of the entrances and exits. These decisions are critical for automated trucks that to enter the freeway and join the ATL and for automated trucks to leave the ATL to exit the freeway. This research presents, through VISSIM microscopic traffic simulation, a series of scenarios that tested the possible locations and lengths of entrances and exits for an ATL relative to the locations of on-ramps and off-ramps. The simulation testbed was along a major truck corridor intersected by two closely spaced interchanges. The corridor consisted of an ATL in the median and three general purpose lanes in the same direction. The design year was 2045. Based on the results of the simulation runs, the recommended distance between the on-ramp from an upstream interchange to the ATL entrance was 10,560 ft (3,220 m). A similar distance is also recommended between the exit of the ATL and the downstream off-ramp. The recommended length of the ATL’s entrance or exit was 2,400 ft (730 m).