Evaluating Frog Design to Minimize Noise and Vibration and Improve Life-Cycle Costs

The frog is a component of special trackwork where one rail crosses another. Openings called flangeways are provided in standard frogs so that the flanges on the vehicle wheels can pass through. When the wheel passes through the open flangeway at the point of the frog, the wheel tread and frog wing rail surface locations produce high impact forces, noise, and vibration. When frogs must be located near noise- and vibration-sensitive land uses, they are often identified as a noise or vibration impact during the environmental process and require mitigation. Low-impact frog designs can be an effective mitigation measure because reducing the impact also reduces the resulting noise and vibration levels. However, there is almost no data on how much low-impact frog designs reduce noise and vibration levels. In addition, many agencies are hesitant to adopt new frog designs. The primary objective of this research is to determine the reduction in noise and vibration provided by alternative low-impact frog designs. The secondary objective is to provide guidance to transit agencies on how to select appropriate frog designs for noise and vibration mitigation and how to maintain good noise and vibration performance through necessary maintenance practices.


  • English


  • Status: Proposed
  • Funding: $300000
  • Contract Numbers:

    Project D-22

  • Sponsor Organizations:

    Transit Cooperative Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC    20001

    Federal Transit Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Project Managers:

    Parker, Stephan

  • Start Date: 20220621
  • Expected Completion Date: 0
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01789438
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project D-22
  • Files: TRB, RIP
  • Created Date: Nov 23 2021 6:56PM