Potential Effects of Heavy Vehicles on Operations of Super 2 Highways

Increasing volumes, specifically heavy truck volumes, have an increasingly greater effect on operations on the nation’s two-lane highways. Various strategies have been implemented to reduce delay and increase capacity, particularly the use of marked passing zones and the addition of periodic passing lanes to allow faster vehicles to pass slower vehicles and to disperse platoons. However, much existing guidance and previous research focused on those design features in the context of passenger vehicles. As the volume of heavy vehicles increases, particularly in high-demand corridors such as those related to energy exploration or manufacturing distribution, so does the number of individual trucks and truck convoys that can further erode operational characteristics on two-lane highways. This paper summarizes existing guidance and recent literature on passing treatments and design guidelines for passing sight distance, passing lanes, and passing zones. This paper also presents results from a proof-of-concept exercise to demonstrate potential effects of trucks on extending the lengths of passing sight distance for certain scenarios.