Tyre–pavement interaction noise levels related to pavement surface characteristics

In recent years, the quieter pavement surface which can affect traffic noise levels has been needed largely due to increasing public awareness and demand. The objective of this research is to utilise two methods of measuring tyre–pavement interaction noise and to investigate the influence of different pavement characteristics on tyre–pavement noise level. The first method used the close-proximity noise trailer and the second method used on-board sound intensity measurement. The pavement characteristics considered are pavement texture and smoothness, air voids, pavement stiffness, and nominal maximum aggregate size (NMAS) of asphalt mixtures. The tyre–pavement noise was measured by different techniques from various types of pavement sections in the National Center for Asphalt Technology test track. Testing was conducted on four major family groups of Superpave fine and coarse graded, open-graded friction course, and stone matrix asphalt mixes from 2009 Test Track research cycle to evaluate the changes over time. Relative significance analysis is performed to detect the combined effect of pavement texture and smoothness, air voids, pavement stiffness, and NMAS on tyre–road noise levels. The results show that the noise levels vary widely according to pavement surface type. The evaluation confirms that macrotexture increases the low-frequency noise and higher air void content reduces the high-frequency noise level, while other surface characteristics were found to have less influence on noise levels. The content of this study can be used in the vehicle and pavement noise development process to decrease the tyre–pavement interaction noise and for pavement design and construction to determine appropriate quieter pavement surfaces.