Enhancement of Construction Noise Prediction Tool (RCNM Version 2)

In reaction to ever growing public concern and complaint about construction noise, the Federal Highway Administration (FHWA) developed the Roadway Construction Noise Model (RCNM) in February 2006. The RCNM model, which was the first major update on the subject in over 35 years, was based on the construction noise model developed and utilized at the Central Artery/‌Tunnel Project (The Big Dig) in Boston. It has since gone on to be recommended for use by FHWA, state and municipal noise regulations (e.g. NYC Construction Noise Regulation) as well as numerous project-specific noise specifications. It has become the de-facto reference source for construction equipment noise emissions and predictions, and is routinely used by projects for planning and environmental assessment, construction noise mitigation plans, regulations development, specification enforcement, and legal cases involving construction noise. However, RCNM has limitations and uses simplified assumptions (e.g. equipment usage factors) that limit its flexibility and accuracy. An improved version is needed to make the model more flexible and accurate for use in urban, suburban and rural environments. For example, the construction equipment noise database in RCNM provides only broadband Lmax A-weighted levels, the calculation of time-dependent noise metrics is done by estimation, and there is no accounting for excess attenuation provided by ground effects and air absorption losses. Also, the current version of RCNM only allows for rough estimates of noise reduction from barriers and other obstacles, so an enhanced algorithm is needed to account for such attenuation. The result is that the model can overpredict construction noise levels and result in a high level of uncertainty for the effectiveness of noise reduction efforts. An improved tool is needed for predicting construction noise levels and the effects of noise reduction efforts to reduce the potential for public complaints and ensure compliance with state, local, and project-specific noise restrictions. The tool could be either an update to the existing RCNM or the development of a new model. An improved tool would include an updated equipment noise emission database on a spectral basis; the ability to predict time-dependent noise metrics of interest such as Lmax, Leq, L10, L90, and others; and improved capability for use over greater distances and terrains. This research will help state transportation departments reduce public complaints, reduce noise control costs, avoid litigation, and improve project delivery. The objectives of this proposed research are to expand and/or establish a new construction equipment noise emission database in spectral format by measuring equipment noise emissions from numerous equipment engaged in construction operations as available from project job sites nationwide; expanding the equipment noise emission database to include standard time-dependant noise metrics such as Lmax, Leq, L1, L10, L50, L90, and L99; expanding the model's calculation algorithm to include ground attenuation effects and air absorption, on a spectral basis, to make the model more accurate over greater distances; developing an algorithm module to calculate noise reduction (insertion loss) due to barriers, berms, and intervening objects on a spectral basis; and developing a user's guide to reflect and describe use of the tool. Reducing construction noise is an ongoing challenge, especially for major construction projects. The challenge is both for addressing public concerns and ensuring compliance with state, local, and project-specific noise restrictions. Examples of these challenges resulting in high compliance costs, extensive coordination with local officials, and robust public response strategies include the Big Dig project, T-Rex project, Wilson Bridge project, Alaska Way Viaduct project, and World Trade Center Rebuild project. Construction noise is a controllable public impact and need not be viewed as simply an unavoidable inconvenience. An improved construction noise modeling tool would allow for more accurate and reliable construction noise predictions and impact assessments on a proactive basis, thus allowing project sponsors to implement appropriate noise mitigation measures. Further, improved accuracy and the ability to model specific project circumstances in greater detail would reduce mitigation costs.

Language

  • English

Project

  • Status: Proposed
  • Funding: $250000.00
  • Contract Numbers:

    Project 25-49

  • 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

  • Start Date: 20141114
  • Expected Completion Date: 0
  • Actual Completion Date: 0
  • Source Data: RiP Project 37530

Subject/Index Terms

Filing Info

  • Accession Number: 01543478
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 25-49
  • Files: TRB, RiP
  • Created Date: Nov 15 2014 1:01AM