Practitioners’ Guide for Lighting at Innovative Intersections/Interchanges, including Roundabouts

Innovative intersections and interchanges are junctions of two or more roads that do not use traditional intersection or interchange layouts. Examples include diverging diamonds, restricted crossing U-turns, displaced left turns, and roundabouts. Most innovative intersections/interchanges installed in the United States have roadway lighting, in part because lighting is supported by Federal Highway Administration’s (FHWA’s) Alternative Intersection and Interchange Report, and NCHRP Report 672: Roundabouts: An Informational Guide, second edition. Lighting, however, adds significantly to construction and maintenance costs, which can be a barrier to constructing roundabouts and other innovative intersections/interchanges. Furthermore, lighting can be a barrier in settings where communities are concerned about light pollution. Research is needed to help practitioners determine (1) under what conditions lighting is justified at roundabouts and other innovative intersections/interchanges and (2) at locations where lighting is justified, what are the best lighting design practices. The objective of this project is to develop a practitioners’ guide for lighting at innovative intersections/interchanges, including roundabouts that (1) documents quantitative safety benefits associated with lighting for motorists and vulnerable road users (e.g., motorcyclists, pedestrians, bicyclists) at innovative intersections/interchanges; (2) establishes evidence-based criteria for determining whether or not to install lighting; and (3) identifies best practices, noteworthy considerations, and emerging approaches for lighting design at innovative intersections/interchanges, including roundabouts..


  • English


  • Status: Proposed
  • Funding: $500000
  • Contract Numbers:

    Project 05-27

  • 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:

    Retting, Richard

  • Start Date: 20221010
  • Expected Completion Date: 0
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01847360
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 05-27
  • Files: TRB, RIP
  • Created Date: May 26 2022 4:53PM