Work Zone Capacity Methods for the Highway Capacity Manual

Work zone mobility is a major concern for transportation agencies due to maintenance and construction needs and increasing traffic congestion. Nearly 24 percent of non-recurring congestion is caused by work zones and recent federal rules require systematic impact assessment during the planning, design, and construction of projects, as well as development of Transportation Management Plans for all federal-aid highway projects. The emphasis on work zone impact assessment, which includes analysis of Maintenance of Traffic (MOT) alternatives, mitigation strategies, and road-user costs, has resulted in the rapid increase in development and use of related analytical methodologies, modeling, and tools. These analytical tools are used by transportation agencies to make multi-million dollar MOT decisions, determine work hours and project scheduling, and develop incentives/disincentives and lane rental fees. Selection of suboptimal MOT alternatives and other impact mitigation strategies may result in increased congestion, degraded travel time reliability, and increased rear-end crashes due to queues. A good understanding of work zone capacity is important for the proper use of spreadsheet/sketch-planning tools as well as simulation tools. The Highway Capacity Manual (HCM), the fundamental reference document for determining roadway capacity and level of service, has limited information on freeway work zone capacity, and additional information is needed to address the range of work zones for the various facility types and conditions. Guidance is also needed on how to calibrate microscopic simulation models to accurately account for work zone capacities. The objective of this research is to develop improved material on the capacity of work zones suitable for incorporation into the HCM. The material should (1) define work zone capacity, (2) describe procedures for field measurement of work zone capacity, (3) present analytical techniques or methods to estimate the capacity of work zones, (4) provide recommendations for the calibration of work zone capacity in microscopic simulation models, and (5) include example problems. Although consideration of diverting traffic is important in analyzing MOT alternatives, it is beyond the scope of this project.


  • English


  • Status: Proposed
  • Contract Numbers:

    Project 03-107


  • Sponsor Organizations:

    Federal Highway Administration

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

    National Cooperative Highway Research Program

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

    Derr, B

  • Start Date: 20111208
  • Expected Completion Date: 0
  • Actual Completion Date: 0
  • Source Data: RiP Project 29074

Subject/Index Terms

Filing Info

  • Accession Number: 01463251
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 03-107, 600000
  • Files: TRB, RiP, USDOT
  • Created Date: Jan 3 2013 2:20PM