Operational and Safety Considerations in Making Lane Width Decisions on Urban and Suburban Arterials

In an era of multimodal design and expensive right-of-way, agencies must make decisions on how to best accommodate users of the roadway system within limited budgets. One of the driving decisions is how wide the travel lanes should be while balancing these interests and operational and safety perspectives. A few recent research projects have examined the relationship between lane width and safety on urban and suburban arterials. These studies found no general indication (with a few exceptions) that the use of lanes narrower than 12 feet increased crash frequencies. While the research provided excellent insight into lane width/safety relationships, it did not address speed, volume, transit, heavy vehicles, on- and off-street neighboring spaces (e.g., turn lane, bike lane, on-street parking, shoulder width, curb and gutter, another lane next to lane of interest, or the proximity of objects such as utility poles, trees, or street furniture on the roadside), bicycle and pedestrian use, and shared versus exclusive lane use. Therefore, additional research is needed to better answer these questions. The objectives of this research were (1) to investigate the effects of urban and suburban arterial lane widths on operations and safety for all users, (2) produce guidelines for practitioners to determine lane configuration for reconstruction and new construction projects, and (3) propose appropriate revisions to the AASHTO Green Book.


  • English


  • Status: Completed
  • Contract Numbers:

    Project 03-112

  • Sponsor Organizations:

    Federal Highway Administration

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

    American Association of State Highway & Transportation Officials (AASHTO)

    444 North Capitol Street, NW, Suite 225
    Washington, DC  United States  20001

    National Cooperative Highway Research Program

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

    Reynaud, David

  • Performing Organizations:


  • Principal Investigators:

    Potts, Ingrid

  • Start Date: 20140804
  • Expected Completion Date: 20171005
  • Actual Completion Date: 20171005
  • Source Data: RiP Project 37722

Subject/Index Terms

Filing Info

  • Accession Number: 01543528
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 03-112
  • Files: TRB, RIP
  • Created Date: Nov 18 2014 1:00AM