RECENT DOT STUDY EVALUATING NCHRP 117 AND TSC HIGHWAY NOISE PREDICTION METHODS

The contribution of the Transportation Systems Center (TSC) to the highway noise prediction program is briefly reviewed, the bases of the TSC and 117 prediction models are outlined, and results are discussed of a comparative study of the TSC and Michgian 117 models. The basic equations for the TSC and 117 models show that the latter is fundamentally an empirical one which the former is based on theoretical considerations. The TSC model, using roadway and barrier endpoints and receiver locations expressed in a Cartesian coordinate system, greatly reduces the structuring of the input case and does not require that the user calculate the various subtended angles. The running of subsequent cases with changes to only individual parameters is more straightforward with the TSC model. Both models were intended for free-flowing traffic and do not behave well in urban or interrupted traffic flow situations. Preliminary results from a comparative study indicate that the values from the TSC model are much higher than the field data; the results of the Michigan 117 model, although not as high, still remain above field data. An analysis is also being made of the field measurements to determine the noise decrease with doubling of distance and the relationship between L sub eq and V/DS for events where one vehicle type predominates.

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  • Accession Number: 00131395
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: May 14 1976 12:00AM