EXPERIMENTAL DATA SUPPORTING THE NCHRP 3-7/3 REVISED DESIGN GUIDE FOR HIGHWAY NOISE PREDICTION AND CONTROL

Field noise data is presented in support of the revised design guide model which contains many changes and modifications to the procedure presented in NCHRP 117/144. Comments are made on the acquisition and analysis of field noise data, and experimental data is presented and analyzed in terms of the noise source model, the free field propagation model, and the "barrier" noise reduction model. The assessment of the source model (predicts the total magnitude of acoustic energy being generated in terms of sound levels and close proximity to the roadway) was performed by selecting noise measurements typically between 25 to 100 ft. from the near lane. Comments are made relating to the gross accuracy of the model. The conclusions are summarized of the analysis of the free field propagation model which predicts how the acoustic energy is propagated between source and receiver. Analysis of results with the barrier noise reduction model (evaluates how obstructions or definable terrain characteristics modify and reduce the noise levels reaching the receiver) show reasonable agreement between measured and predicted values except in the case of berms where the prediction procedure underpredicts by an average of 2.8 dBA. This limited evaluation of the accuracy of the revised guide shows general agreement between the predicted and measured values for the three main components of the model. The data suggest that an accuracy of plus or minus 2.5 dBA may be expected. The need is indicated for further validation studies which incluse complex geometries.

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 18-29
  • Serial:

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Filing Info

  • Accession Number: 00131396
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: May 14 1976 12:00AM