Pavement noise investigation on North Carolina highways: an on-board sound intensity approach

This paper presents the findings on tire-pavement noise on various types of pavements by using an on-board sound intensity (OBSI) method. Mitigation of traffic noise has become an increasingly important consideration for highway agencies when constructing new highways or improving the existing systems. As a competitive alternative for noise mitigation, quieter pavement may provide advantages that noise barriers do not have, or to where sound barriers are not suited. The first step in developing quieter pavement is identifying the noise levels of different types of highway pavements. To reach the ultimate goals of quieter pavement development, this research has focused on the most imperative task, i.e., to measure the noise levels of different types of pavements in North Carolina (NC). Pavement noise levels of 61 highway sites including 153 test sections around 30 counties for nine types of pavements across North Carolina have been investigated. A thorough literature review was conducted and OBSI testing equipment with sound intensity measuring process was established during this study. The results of OBSI data indicate that the tire-pavement noise levels of the six dense graded surface courses in NC are in a lower range, from 98.2 to 99.6 dBA, comparing with other dense graded surface friction courses in other states. The overall findings indicate that relatively quieter pavements have been used in North Carolina. The OBSI data collected will provide valuable information in future research for quieter pavement development and traffic noise management.