PASSING SIGHT DISTANCE DESIGN FOR PASSENGER CARS AND TRUCKS

Safe and effective passing zones on two-lane highways require both adequate sight distance to opposing vehicles and adequate passing zone length. Current design and marking criteria for passing zones on two-lane highways are reviewed. A recently developed model of the kinematic relationships among the passing, passed, and opposing vehicles is employed to evaluate the current design and marking criteria. The model is used both to evaluate the current criteria, which are based solely on passenger cars, and to consider the passing requirements when the passed vehicle, the passing vehicle, or both, are large trucks.