Reliability Implementation Support. Project L55.

To address the challenges of moving people and goods efficiently and safely on the nation's highways, Congress has created the second Strategic Highway Research Program (SHRP 2). Administered by the Transportation Research Board (TRB), SHRP 2 is a targeted, short-term research program carried out through competitively awarded contracts to qualified researchers in the academic, private, and public sectors. SHRP 2 addresses four strategic focus areas: the role of human behavior in highway safety (Safety); rapid highway renewal (Renewal); congestion reduction through improved travel time reliability (Reliability); and transportation planning that better integrates community, economic, and environmental considerations into new highway capacity (Capacity). Under current legislative provisions, SHRP 2 has expanded its efforts to include activities such as office and field pilot tests and product validations that help to prepare research results for implementation. Additional information about the program is available on the website: The major objective of SHRP 2 Reliability research is to greatly improve the reliability of highway travel times by reducing the frequency and effects of events that cause travel times to fluctuate unpredictably. The results of the research program should help local, state, and national agencies reduce travel time variability for travelers and shippers. The Reliability research plan addresses both recurring and nonrecurring congestion with an emphasis on nonrecurring congestion. The following seven potential sources of unreliable travel times (i.e., events that cause variable travel times) were identified: traffic incidents, work zones, demand fluctuations, special events, traffic control devices, weather, and inadequate base capacity. The Reliability focus area targets travel time variation--that frustrating characteristic of the transportation system that means you must allow an hour to make a trip that normally takes 30 minutes. Not only is reliability an important component for travelers and shippers, it is also an area of the congestion problem in which transportation agencies can make significant gains even as travel demand grows. The seven sources of unreliability account for approximately half of total delay. Reducing reliability-related delay will also result in fewer crashes, reduced vehicle emissions and fuel use, and other benefits. These benefits can be realized through a mix of leading-edge research into a better understanding of strategies and their consequences, new technology and practices, and reducing institutional barriers so that our existing knowledge can be more fully exploited. The goals of the Reliability focus area are built around the first five of the seven sources of unreliable travel times mentioned above. Work on weather-related issues will be coordinated with the Road Weather Management R&D program under way at the Federal Highway Administration (FHWA). Related research on inadequate base capacity is being undertaken in the SHRP 2 Capacity focus area and elsewhere and will be closely coordinated by SHRP 2 staff.


  • English


  • Status: Completed
  • Contract Numbers:

    Project L55

  • Sponsor Organizations:

    Strategic Highway Research Program 2

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC    20001
  • Project Managers:

    Pedersen, Neil

  • Performing Organizations:

    Cambridge Systematics

    555 12th Street
    Suite 1600
    Oakland, CA  United States  94607
  • Start Date: 20130312
  • Expected Completion Date: 0
  • Actual Completion Date: 20150301
  • Source Data: RiP Project 38335

Subject/Index Terms

Filing Info

  • Accession Number: 01547523
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project L55
  • Files: TRB, RiP
  • Created Date: Dec 11 2014 1:00AM