Tire/Pavement Noise Intensity Testing in Europe: The NITE Study and Its Relationship to Ongoing Caltrans Quiet Pavement Activities

摘要

Traffic noise has become a growing public concern and the California Department of Transportation (Caltrans) has responded by initiating a number of studies to examine the impact various standard pavements have on traffic noise levels. Four very different acoustical studies and preliminary results are presented. Through these studies, Caltrans developed a quick, accurate, inexpensive, and portable method of equitably measuring and comparing tire/pavement noise levels. The measurement method utilizes sound intensity (SI) and was first used by General Motors in a test track environment for tire development. Caltrans adopted this technology as an alternative to the two existing sound pressure methods currently used in Europe - Statistical Passby (SPB) and Close Proximity (CPX). Using sound intensity, Caltrans and the Arizona Department of Transportation developed a database of pavement acoustic characteristics. The European community has been experimenting with quiet pavements for many years, and in May 2004, the Federal Highway Administration (FHWA) and the American Association of State Highway and Transportation Officials (AASHTO) jointly sponsored an international scanning tour to examine European quiet pavement technology. In September 2004, Caltrans, General Motors, and the FHWA sponsored a follow-up study that used the sound intensity technology to measure and compare some of the European quiet pavements seen on the scanning tour to the California and Arizona quiet pavements. The Noise Intensity Testing in Europe (NITE) study is the first definitive comparison of quiet pavements on multiple continents. Among the many findings of the NITE study, the principle conclusion is that several of the quietest ‘off-the-