Passenger car equivalents of trucks under lane restriction and differential speed limit policies on four lane freeways

Abstract

Lane restriction for trucks and differential speed limits for trucks and cars are becoming more common and feasible policies to improve the efficiency and safety of a freeway. It is believed that passenger car equivalents for trucks are impacted by these non typical freeway operating conditions, which are not explicitly addressed by the latest edition of the Highway Capacity Manual. Using simulated and real world data an elevated 18- mile four lane freeway was modeled under the restriction policies. The section which was used as a test bed was simulated under various control variables. Some of the control variables used were speed distributions from the field data, truck percentages in the traffic mix and the compliance rate to the restriction policies. The simulated results were compared with the corresponding values in HCM and observations were made which can be used for further research. The simulated results show that the ET values decreases with increase in truck percentages under the influence of the truck restrictions due to “platooning effect” caused due to increase in the truck percentage.