Dr. Laurence R. Rilett
Date of this Version
Hurtado-Beltran, A. 2021. "A Methodology for Estimating Capacity and Passenger Car Equivalents for Connected and Automated Vehicles Traveling on Freeways." Doctoral dissertation, Department of Civil and Environmental Engineering, University of Nebraska-Lincoln.
Recently, there has been a significant amount of research related to heavy trucks operating as connected and autonomous vehicles (CAVs). In order to understand the potential impact on the freeway system of CAV technologies, analyses should be conducted using the standard US methodological framework. In the current version of the Highway Capacity Manual (HCM-6), equal-capacity passenger car equivalencies (EC-PCEs) are used to account for the effect of heavy trucks on capacity and quality of service analyses. It is argued in this dissertation the HCM-6 EC-PCE methodology for basic freeway and multilane highway segments can be used to explore a wide variety of traffic situations beyond the scope of the existing results including those related to CAV technologies. However, there are various shortcomings to address before applying the methodology for these purposes.
This dissertation develops new strategies to improve the current state-of-the-art methodology for estimating freeway capacity and PCEs. Specifically, this dissertation develops consistent metrics for the HCM-6, introduces simpler regression model structures for fitting simulated and estimated data, and proposes a replicable microsimulation framework. In general, it was demonstrated the proposed approaches can be successfully applied to the estimation of EC-PCEs for both CAVs and non-CAVs scenarios.
The new techniques proposed for capacity modeling and EC-PCE estimation can be used by engineers and traffic agencies for analyzing any traffic condition outside the HCM-6. It is vital all future EC-PCE analyses are performed using the same standard methodological framework to produce comparable results that can be applied consistently in the HCM-6.
Advisor: Laurence R. Rilett