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The National Academies

NCHRP 08-135 [Final]

Reliability and Quality of Service Evaluation Methods for Rural Highways

  Project Data
Funds: $400,000
Research Agency: University of Florida
Principal Investigator: Scott Washburn
Effective Date: 12/8/2020
Completion Date: 9/8/2023

NCHRP Research Report 1102 presents a guide for traffic analysis of rural highways that connects the individual highway segments into a connected, cohesive, facility-level analysis. The guide describes the development of an automobile level of service methodology for rural highways, the development of guidelines for assessing historical travel time reliability for rural highways, an overview of analysis methods for cycling on rural highways, and recommendations for bicycle operations research. The guide should be of interest to state departments of transportation and other agencies charged with monitoring, maintaining, and improving rural highways of regional or statewide importance.

Rural highways account for a significant portion of the national highway system and serve many vital mobility purposes. Rural highways often span long distances and may consist of segments with a variety of cross-section elements as well as intersections with different traffic controls. The Highway Capacity Manual (HCM), the standard reference for traffic analysis methodologies, contains analysis methodologies for all the individual segments or intersections that may comprise a rural highway; however, it does not include a methodology or guidelines for connecting the individual roadway segments into a connected, cohesive, facility-level analysis. 

Under NCHRP Project 08-135, “Reliability and Quality of Service Evaluation Methods for Rural Highways,” the University of Florida was asked to develop (1) reliability and quality of service analysis methodologies for rural highway facilities consistent with existing HCM methods and (2) a guide on the application of the analysis methodologies. The guide is intended to assist with the evaluation of rural highways in motorized vehicle traffic operations per HCM analysis methods and probe vehicle data analysis methods, and it provides an overview of alternative analysis methods for bicycles and recommended bicycle operations research. The guide is organized into three main parts: analysis methodology descriptions; case studies using real-world routes to demonstrate the analysis methodologies in the guide; and an overview of the component HCM analysis methodologies that are incorporated in the rural highway analysis methodology for automobiles.

In addition to NCHRP Research Report 1102, a conduct of research report summarizing the entire research effort, to be published as NCHRP Web-Only Document 392 is available on the TRB website at trb.org.