Investigations of Environmental Effects on Freeway Acoustics (original: Environmental Measurements in support of traffic generated noise)

The authors present a generalized terrain PE (GTPE) model for sound propagation in non-uniform terrain following the work of Sack and West (1995). Results for simplified terrain cases illustrate the new model’s capabilities and the effects of terrain in a neutral atmosphere. The model is extended by deriving a reflection scheme to account for two-way propagation. Thus, their model enables the study of backscatter from vertical terrain features and forward propagation of traffic noise in complex terrain. Future developments will extend the reflection scheme to terrain features with arbitrary angles. Future possibilities include coupling the sound model with flow calculation software to determine the flow response to terrain and the sound field response to perturbed flow. Additionally, the authors apply ARW-WRF v3.2’s new option of vertical nesting within the finest nest to a numerical experiment studying highway noise pollution in the Phoenix metropolitan area. This experiment was conducted for comparison on November 7, 2006, in Phoenix by Ovenden et al (2009). Vertical profiles with near-ground resolution finer than 20 m were extracted for input into a sound propagation model to produce forecasts of noise pollution from a highway line segment noise source. Vertical nesting improved the resolution of finer structures in the temperature and velocity profiles. Ovenden et al. (2009) previously demonstrated sensitivity of the resultant sound field within 600 m of the source to input effective sound speed vertical profiles, Ceff (z), in the lowest 300 m of the planetary boundary layer. Hence, resolution of such features is important when forecasting Ceff (z) for use in the highway noise propagation model.

Language

  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Appendices; Figures; References; Tables;
  • Pagination: 78p

Subject/Index Terms

Filing Info

  • Accession Number: 01484272
  • Record Type: Publication
  • Report/Paper Numbers: FHWA-AZ-13-605-2
  • Contract Numbers: SPR 000-1(169) 605-2
  • Files: TRIS, ATRI, USDOT, STATEDOT
  • Created Date: Jun 12 2013 3:23PM