New Rural Highway Facility Traffic Operations Analysis Methods

Abstract: Rural highways account for a very significant portion of the national highway system and serve many vital mobility purposes. Rural highways, which often span long distances, may consist of segments with a variety of cross-section elements (two-lane highway, multilane highway, passing lane sections) as well as intersections with different traffic controls (signal control, stop control, roundabouts with yield control).
The Highway Capacity Manual (HCM), the standard reference for traffic analysis methodologies in the U.S., contains analysis methods for all of the individual segments and intersections that may comprise a rural highway; however, it does not include a method, or guidance, for connecting the individual roadway segments into a connected, cohesive, facility-level analysis.
NCHRP Project 08-135, Reliability and Quality of Service Evaluation Methods for Rural Highways, resulted in the development of reliability and level of service analysis methodologies for rural highway facilities, consistent with existing HCM methods. These analysis methods are documented in the primary product of this project, a user guidebook. The guidebook is intended to assist transportation agencies charged with monitoring, maintaining, and improving rural highways of regional or statewide importance.
More specifically, the guidebook is intended to assist with the evaluation of rural highways in three areas: 1) motorized vehicle traffic operations per HCM analysis methods, 2) motorized vehicle traffic operations per probe vehicle data analysis methods, and 3) overview of alternative analysis methods, to the HCM, for bicycles and recommendations for future bicycle operations research needs. Also developed as part of this project are computational tools that implement the analysis methods of the guidebook and are available at no cost through a GitHub site. This presentation will provide an overview of the content of the guidebook and the complimentary computational tools.