Evaluating the Impacts of Real-Time Warnings and Variable Speed Limits on Safety and Travel Reliability during Weather Events

Road Weather Management (RWM) has advanced significantly with new sources of road weather data and greater opportunities for more active management of roadways through direct communication with drivers. Pilot RWM applications and strategies have proven effective during weather events. Actively managing the system using variable speed limits (VSL) and real-time motorist warnings (RTW) based upon real-time weather and road condition data have proven to be effective strategies. However, additional research is needed to advance the practice and application of VSL and RTW nationally. Because the effectiveness of these solutions depends on driver behavior, infrastructure owner operators (IOO) must understand the operational environment and the anticipated responses of drivers. For either VSL or RTW to be effective, the IOOs must know the current and anticipated environmental conditions, understand their impacts on mobility and safety, and formulate effective traffic management strategies to alert drivers. IOOs must understand how drivers receive VSL and RTW messages; interpret and integrate these messages with their own observations of roadway conditions; and react during different types of weather events. IOO's must also understand the best ways to capture drivers' attention; learn whether drivers respond differently to advisory or regulatory messaging; and understand the influence of other human factors and driver behaviors. Consistent and effective messaging would help IOOs achieve safer, more reliable transportation during adverse weather. The objectives of this research are to (1) identify strategies and information needed to formulate effective messaging (including VSL and RTW) to elicit appropriate driver behavior and aid highway safety and mobility; (2) describe how to convey messaging with consideration of message locations, content, platform, and timing; and (3) identify the means to determine the effectiveness of the deployment of real-time messaging, including VSL and RTW, on safety and travel reliability.


  • English


  • Status: Active
  • Funding: $400000
  • Contract Numbers:

    Project 03-142

  • Sponsor Organizations:

    National Cooperative Highway Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  United States  20001

    American Association of State Highway and Transportation Officials (AASHTO)

    444 North Capitol Street, NW
    Washington, DC  United States  20001

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Project Managers:

    Crichton-Sumners, Camille

  • Performing Organizations:

    University of Connecticut, Storrs

    Connecticut Transportation Institute
    270 Middle Turnpike, Unit 5202
    Storrs, CT  United States  06269-5202
  • Principal Investigators:

    Ivan, John

  • Start Date: 20220804
  • Expected Completion Date: 20250804
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01772207
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 03-142
  • Files: TRB, RIP
  • Created Date: May 25 2021 12:20PM