Impact of CAV Truck Platooning on HCM-6 Capacity and Passenger Car Equivalent Values

Recently, there has been a significant amount of research related to heavy trucks operating as connected and autonomous vehicles (CAVs). As argued in this paper, to understand the potential impact on the freeway system of CAV technologies, analyses should be conducted using the standard US methodological framework. Consequently, this paper uses the exact Highway Capacity Manual, Sixth Edition (HCM-6) equal capacity passenger car equivalent (EC-PCE) methodology to estimate capacity and EC-PCEs for CAV truck platoons on freeway segments. It was found that EC-PCE values for CAV trucks are, on average, 34.3% lower compared to the values for non-CAV trucks, indicating that CAV platoons can have a positive effect on highway capacity. The amount of decrease is a function of a number of CAV operational assumptions, and these are studied through a sensitivity analysis. This paper demonstrates that the effect of CAV truck platoons can be modeled using the standard HCM-6 approach, and the methodology allows meaningful comparisons so that traffic agencies can better prepare for the adoption of CAV technologies.