The calculation of the directivity for the sound emission from moving vehicles is important for predicting the traffic noise by means of computer and to improve the protections design for noise reduction. The horizontal directivity of noise from moving vehicles can be calculated by a procedure and it is a function of the following data: vehicle speed, recorded signal and instant of passage from the receiver, relative humidity and atmospheric temperature. Furthermore, relationship between sound level, speed and angle has been analysed plotting polar diagrams from a random sample of light and heavy vehicles. The real problem has many difficulties. For instance the speed of the vehicles was not constant, the simultaneity of the emission with background noise, the micro-meteorological inhomogenities caused by the source when it is passing, and the impossibility of reproducing exactly each event. For the covering abstract see IRRD E104312.


  • English

Media Info

  • Features: References;
  • Pagination: p. 223-8

Subject/Index Terms

Filing Info

  • Accession Number: 00790186
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • ISBN: 0-9622072-3-3
  • Files: ITRD
  • Created Date: Apr 11 2000 12:00AM