Innovative Mitigation Strategies for Highway Noise

The objective of this project is to identify innovative methods to avoid transportation noise impacts or to reduce impacts where traditional noise mitigation methods are not feasible and reasonable. These methods could help reduce the overall cost of a project, when compared to what it would cost if traditional noise mitigation was used, and provide relief to communities where traditional methods are not applied. In addition, these methods may increase the effectiveness of traditional mitigation methodologies when used in conjunction. Highway noise impacts require agencies to implement expensive noise abatement measures when feasible and reasonable to protect nearby communities. Highway noise mitigation typically uses noise barriers as the most common abatement measure. Due to the high cost of noise walls (an average of $2 million a mile for a single direction) and acoustic feasibility or constructability issues, barriers may not be built, leaving portions of communities unmitigated. This project will identify nontraditional methods to reduce highway noise. There are methods currently being applied, as well as promising theoretical methods, focused on changing project design aspects or determining better material selection to reduce highway noise. In some cases, these methods would result in avoiding noise impacts and eliminating the need to build noise walls. In other cases, these methods would help to reduce noise levels where traditional methods are not feasible or reasonable or desired by adjacent residents. The objective of this research is to gather information on the use of methods including, but not be limited to: (1) solid safety barriers in place of guard rails; (2) sound-absorbing ground surface adjacent to the highway; (3) vegetated swales/retention basins; (4) quieter pavements for highways and highway shoulders; (5) quieter bridge decks and joints; (6) quieter rumble strips; (7) retrofitted absorptive or vegetative sound wall treatments; (8) retrofitted lightweight noise wall overhangs; (9) bike path and bike path separation zones; (10) on-board sound intensity measurements to identify loud sections for targeted rehabilitation for highways; and (11) small height berms (3’-6’). Also of interest are methods that resulted in worsening noise effects.


  • English


  • Status: Proposed
  • Funding: $250000
  • Contract Numbers:

    Project 25-57

  • 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:

    Hartell, Ann

  • Start Date: 20180709
  • Expected Completion Date: 0
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01672251
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 25-57
  • Files: TRB, RiP
  • Created Date: Jun 18 2018 3:03PM