Impact identification of traffic flow and road age on traffic noise emission via an approach of relative traffic noise pressure index

In this study, a series of field experiments are conducted on a highway to identify the effects of traffic flow and pavement operation time on traffic noise emission. The traffic noise at different times and pavement durations is investigated. Logarithmic functions are established in the investigations to fit the measurements of traffic flow and traffic noise at two measurement sites. An indicator named the relative traffic noise pressure index is proposed for quantitatively evaluating the effects of the road pavement ageing on traffic noise emission. The results of the research indicated that the repaved road surface may effectively reduce the traffic noise level when the operation time of the road surface is relatively short. It is also shown in the present research that the relative traffic noise pressure index proposed is an effective measure for evaluating the traffic noise with respect to the traffic flow and road pavement ageing.