• Skip to primary navigation
  • Skip to main content
Logo

Work Zone Safety Information Clearinghouse

Library of Resources to Improve Roadway Work Zone Safety for All Roadway Users

  • About
  • Newsletter
  • Contact
  • X
  • Facebook
  • LinkedIn
  • Work Zone Data
    • At a Glance
    • National & State Traffic Data
    • Work Zone Traffic Crash Trends and Statistics
    • Worker Fatalities and Injuries at Road Construction Sites
  • Topics of Interest
    • Commercial Motor Vehicle Safety
    • Smart Work Zones
    • Work Zone Safety and MobilityTransportation Management Plans
    • Accommodating Pedestrians
    • Worker Safety and Welfare
    • Project Coordination in Work Zones
  • Training
    • Online Courses
    • FHWA Safety Grant Products
    • Toolboxes
    • Flagger
    • Certification and
      Accreditation
  • Work Zone Devices
  • Laws, Standards & Policies
  • Public Awareness
  • About
  • Events
  • Contact
  • Search
Publication

Capacity for North Carolina Freeway Work Zones

Author/Presenter: Dixon, Karen K.; Hummer, Joseph E.; Lorscheider, Ann R.
Abstract:

Work zone capacity values for rural and urban freeways without continuous frontage roads were defined and determined. Data were collected using Nu-Metrics counters and classifiers at 24 work zones in North Carolina. The research included analysis of speed-flow behavior, evaluation of work zone sites based on lane configuration and site location, and determination of the location within the work zone where capacity is lowest. It was shown that the intensity of work activity and the type of study site (rural or urban) strongly affected work zone capacity. The data suggested that the location where capacity is reached is also variable based on the intensity of work. For heavy work in a two-lane to one-lane work zone configuration, the capacity values proposed at the active work area are approximately 1,200 vehicles per hour per lane for rural sites and 1,500 vehicles per hour per lane for urban sites. It is recommended that two distinct volumes be used when queue behavior in a freeway work zone is analyzed. The collapse from uninterrupted flow (designated work zone capacity) and the lower queue-discharge volume both should be considered.

Source: Transportation Research Record: Journal of the Transportation Research Board
Volume: 1529
Issue: 1
Publisher: Transportation Research Board
Publication Date: 1996
Source URL: Link to URL
Publication Types: Books, Reports, Papers, and Research Articles
Topics: Behavior; Rural Highways; Urban Highways; Work Zone Capacity; Work Zones

Copyright © 2025 American Road & Transportation Builders Association (ARTBA). The National Work Zone Safety Information Clearinghouse is a project of the ARTBA Transportation Development Foundation. It is operated in cooperation with the U.S. Federal Highway Administration and Texas A&M Transportation Institute. | Copyright Statement · Privacy Policy · Disclaimer
American Road and Transportation Builders Association Transportation Development Foundation, American Road and Transportation Builders Association U.S. Department of Transportation Federal Highway Administration Texas A&M Transportation Institute