Experimental modelling of tyre/road noise from road texture spectra on rubberized road surfaces

Road traffic noise is one of the most common sources of acoustic pollution in urbanized environments and, therefore, its mitigation is fundamental for urban planning. Since tyre/road interaction represents the main contribution to overall road traffic noise, the use of low noise road surfaces represents a useful way for reducing the acoustic impact of road traffic, acting on the main generation mechanism of noise. In this work, both acoustic performances and road texture of several low noise rubberized surfaces and conventional road surfaces were measured and compared. In particular, acoustic performances were monitored using the CPX method, while road texture measurements were performed using a laser triangulation sensor. Road profiles were processed with a tyre envelopment algorithm called indenter method and the spectra of the resulting signal was compared with the CPX spectra on each road surface. Findings show that surfaces with crumb rubber within the mixture behave differently compared to conventional surfaces at high frequency, while noise at frequencies lower than 1 kHz seems unaffected by the presence of crumb rubber.