Highway traffic noise is a major environmental issue all over the world. This is particularly annoying to residents who live nearby major transportation corridors. Noise pollution adversely affects the quality of their life. It also causes sleep disturbance and anxiety. The most commonly used noise abatement technique is the use of noise barrier walls, which is costly and not always effective. Reducing the tire–pavement noise at the source is a viable alternative to cut down the noise level. This study examined the use of an impedance tube to measure the acoustic absorption of asphalt mixtures in the laboratory. The effect of various parameters on the acoustic absorption was investigated including aggregate gradation, aggregate type, binder type, percent air voids, and specimen thickness. In addition, factors that could affect the acoustical performance of asphalt mixtures after pavement construction were also investigated including air void structure, surface texture, temperature, and surface conditions. Percent air voids and layer thickness were found to have a significant influence on the acoustic absorption of asphalt mixtures. An analytical model was proposed to estimate the acoustic absorption coefficient of asphalt mixtures during the design stage. A good correlation was found between predicted and measured absorption coefficients in the laboratory. In addition, a double-layer system of asphalt mixtures was found to be effective in providing improved acoustical performance that overcomes the issues associated with the use of open-graded friction course as a wearing surface.

There is pressing and growing demand from the public to design and construct roads with a low noise level. This paper investigated the acoustic performance of asphalt pavements in the State of Qatar to assist transport authorities in designing and constructing quieter pavements. In this study, a field-testing setup was assembled to measure the tire-pavement noise of dense-graded asphalt (DGA) pavements at the source using the on-board sound intensity (OBSI) method. The repeatability and reproducibility of test results demonstrated that the assembled OBSI test setup could measure the sound intensity with excellent repeatability and reproducibility. The measured noise level of existing pavements varied from 101.8 dBA to 106.2 dBA depending on the age of pavement sections. Measured noise levels of pavements in Qatar were higher than typical DGA pavements in Europe and the US. Test results also demonstrated that the acoustic performance of pavements in Qatar deteriorates faster compared to those in the US and Europe. The findings of this study demonstrate that there is a need to consider alternative asphalt mixture designs in Qatar and the Arabian Gulf. The results also showed a good correlation between the mean texture depth of studied pavement sections and noise level, especially at the low-frequency range.

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Transverse rumble strips (TRS) acts as a traffic calming device to alert inattentive drivers, however, inappropriate design may generate excessive noise level which cause annoyance among the nearby residents. This study attempts to assess community noise annoyance by investigating current TRS designs and characteristics, measuring roadside noise level and traffic characteristics and evaluating noise annoyance due to TRS installation. Middle overlapped (MO), middle layer overlapped (MLO) and raised rumbler (RR) TRS profile types were selected. Noise indices such as A-weighted equivalent continuous sound pressure level (LAeq), sound level exceeding 10% (L10) and 90% (L90) of specified time were measured using sound level meter (SLM) based on ISO 11819 - 1: 2001 Acoustics: Measurement of the influence of road surfaces on traffic noise - Part 1: statistical pass-by (SPB) method. Traffic characteristics such as volume and speed were also measured. Then, community noise annoyance was evaluated in terms of LAeq changes, noise limit comparison by the Department of Environment (DOE) and traffic noise index (TNI) calculation. It was found that there are various TRS profile types with the thickness of only 3mm. Regardless the types, TRS installation has increased the roadside noise level of about 7dBA and exceeded permissible noise limits.