Final Scope
The Level of Service (LOS) concept has been used for over 50 years by state departments of transportation (DOTs) for policy setting, planning, analysis, and communication efforts. Individual adoption of the LOS framework by DOTs has generally been consistent with the Highway Capacity Manual (HCM) although usage and application may vary across different state DOTs. Some agencies may also have tailored their respective LOS definitions and applications for local conditions, multimodal analysis, and threshold values such as adjustment of HCM’s hard-edged LOS category definitions (e.g., extrapolating or delineating failure conditions). Additionally, there are differences in how DOTs use big data and modern communication tools in their LOS analyses.
The objective of this synthesis is to document practices of state DOTs use of the HCM LOS framework for traffic capacity and multimodal analyses.
Information to be gathered includes (but is not limited to):
State DOTs use of LOS as a target or standard for:
o Policy making;
o Planning practices;
o Communication purposes;
o Traffic operations analyses; and
o Multimodal analyses.
How state DOTs determine LOS relative to traffic conditions by:
o Facility type (interrupted vs. uninterrupted); and
o Design hour (peak commute hour, AADT, etc.).
· State DOTs processes for reviewing and updating LOS definitions and applications:
o Harder boundary edge vs. softer definition;
o Multimodal LOS; and
o Delineation of failure conditions (e.g., good F and bad F).
· Extent to which big data, modern technology, and visual tools has been used for LOS analyses and public communications.
Information will be gathered through a literature review, a survey of state DOTs, and follow-up interviews with selected agencies for the development of case examples. Information gaps and suggestions for research to address those gaps will be identified.
Information Resources (Partial):
- Highway Capacity Manual
- NCHRP Report 616 - Multimodal Level of Service Analysis for Urban Streets.
TRB Staff
Arefeh Nasri
Phone: 202-334-2763
Email: anasri@nas.edu
Meeting Dates
First Panel: October 12, 2023, Washington, D.C.
Teleconference with Consultant: November 8, 2023, 10:00-11:00 a.m.
Second Panel: June 25, 2024, Washington, D.C.
Panel Members
Jongsun Won, Federal Highway Administration (FHWA)
Samuel Ahiamadi, Nevada Department of Transportation
Christina Barry, Georgia Department of Transportation
Alex Hainen, University of Alabama
Robert Maffeo, Michigan Department of Transportation
Zhibo Zhang, District Department of Transportation
Cynthia Jones, Transportation Research Board
