Determination of Encroachment Conditions in Work Zones

There were 96,626 crashes in roadway work zones in 2015. This equates to one work zone crash every 5.4 minutes. Every day, 70 work zone crashes result in at least one injury, and every week, 12 work zone crashes result in at least one fatality. Previous research regarding work zone encroachments indicates that there is a higher frequency of fatalities in work zone crashes than nonwork zone crashes (National Work Zone Clearinghouse). Thus, work zones may be an area where significant safety improvements can be made. While current data suggest that work zones have a higher risk for crashes and fatal injuries, data on the impact conditions associated with work zone crashes is poorly documented. More data is needed to identify areas for improvement in the design of work zones and the safety barriers used therein to improve safety in work zones for the traveling public and highway workers. If encroachments for work zones are different than nonwork zones, designers will be able to balance the use of temporary features and optimize the use of public funds by using less expensive barriers. This research is needed to support updates to the Manual for Assessing Safety Hardware (MASH), the Roadside Design Guide (RDG), and the Manual for Uniform Traffic Control Devices (MUTCD). The objective of this research was to evaluate work zone encroachments and develop guidance to improve safety for workers and the traveling public in roadway work zones. The guidance addresses all aspects of work zones from planning (including when to use positive protection) through implementation, and be useable by any entity involved in the life cycle of the work zone.


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  • Status: Completed
  • Funding: $428073
  • Contract Numbers:

    Project 03-134

  • Sponsor Organizations:

    National Cooperative Highway Research Program

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

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590

    American Association of State Highway and Transportation Officials (AASHTO)

    444 North Capitol Street, NW
    Washington, DC  United States  20001
  • Project Managers:

    Retting, Richard

  • Performing Organizations:

    Texas A&M Transportation Institute, College Station

    Texas A&M University System
    3135 TAMU
    College Station, TX  United States  77843-3135
  • Principal Investigators:

    Dobrovolny, Chiara

  • Start Date: 20190620
  • Expected Completion Date: 20221130
  • Actual Completion Date: 20221130

Subject/Index Terms

Filing Info

  • Accession Number: 01669534
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 03-134
  • Files: TRB, RIP, USDOT
  • Created Date: May 21 2018 9:29PM