Operational Aspects of Exclusive Truck Roadways

The continuing increase in truck traffic throughout the state of Texas and beyond and the related safety impacts has prompted the Texas Department of Transportation to sponsor a study entitled “Strategies for Separating Trucks from Passenger Vehicle Traffic.” The primary objective of this research and the subject of this paper was to develop tools for evaluating the need for special truck facilities, specifically development of the capacity and level of service of selected scenarios of exclusive truck roadway through computer simulation. The research team chose the VISSIM program to model truck types, facilities, and terrain that are representative of rural Texas freeways. Findings indicate that capacities of exclusive truck roadways built in the flat to rolling Texas terrain range from 1025 trucks per lane per hour to 1475 trucks per lane per hour. Based on these capacity values, the research then developed levels of service for exclusive truck roadways. For example, the expected growth in three-plus axle trucks along I-35, the busiest roadway for trucks in Texas, will be sufficient to reach level of service E on some segments of a six-lane truck facility by 2022.