Traffic noise in Malaysia
Since the early 1970s, studies regarding the traffic noise problems in Malaysia have been carried out for the major cities. In a study done by Sulaiman and Saion measuring the average daytime noise level during normal traffic conditions on working days, they found out that the mean noise in Kuala Lumpur was the highest (67.4 – 73.6 dBA), where the levels were seen to decrease for roadsides that are further away from the town centre.
Another research done by Sumiani and Asila on noise measurement at the Damansara-Puchong Highway (LDP) which is a major highway in Kuala Lumpur, was published in 2005. It was found that for the three locations on LDP, the equivalent noise level had exceeded 65 dBA.
From 1970s to 2000s, going through almost 30 years, the traffic noise in Kuala Lumpur is still considered very high, exceeding the noise limit set by the Department of Environment (DOE) Malaysia (DOE, 2019). According to the Guidelines for Environmental Noise Limits and Control published by DOE, the recommended permissible noise level for traffic noise is as follow:
| Receiving Land Use Category | LAeq Day (7.00 am – 10.00 pm) | LAeq Night (10.00 pm – 7.00 am) |
Noise Sensitive Areas Low Density Residential Areas | 60 dBA | 55 dBA |
| Suburban and Urban Residential (Medium and Density) | 65 dBA | 60 dBA |
| Commercial and Mixed Development | 70 dBA | 65 dBA |
| Industrial | 75 dBA | 70 dBA |
Table: LIMITING SOUND LEVEL (LAeq) FROM ROAD TRAFFIC (FOR NEW ROADS AND/OR REDEVELOPMENT OF EXISTING ROADS)
Though not much research report can be found for the most recent traffic noise in Malaysia, the values may not differ by much as compared to previous records due to the increase in registered vehicles, as stated before. Of course, this is purely said with an assumption that all the registered vehicles are used on-road throughout the year.
Noise mitigation measures for traffic noise
Typically, noise barriers are used as a noise control measure in Malaysia. The installation of noise barriers along the roads or highways has been proven effective by lowering the noise transmitted to the surrounding residential areas to achieve the noise limit set by DOE, hence increasing the comfort and living quality of the residents. The designs of noise barriers must meet the requirements set by DOE, based on the Environmental Impact Assessment (EIA), where the current and future traffic volume and conditions should be taken into account. Studies have been done to investigate the effectiveness between concrete hollow block barriers and panel concrete barriers in shielding highway noise. Generally, the insertion losses for both types of barriers are due to the diffraction and reflection of noise waves on the solid flat surfaces of the walls. It has been proven that the cavities inside both concrete hollow blocks and concrete panel barriers works great in absorbing the highway traffic noise.
Although noise barriers have been proven effective, it is not a sustainable way to solve the traffic noise issue in the future years. This is because noise barriers are very expensive, and some may be less effective especially at the top of their edges due to diffraction. Aside from using well-designed barriers, natural methods like allocating plants can be applied as noise absorptive methods. The most imperative part is that the absorption “wall” must be of sufficient height and surface density to ensure the effectiveness in absorbing noise.