If you are living in a huge city or town centre, you can relate to today’s topic for sure.
For the past decade, Malaysia has experienced a significant development in many aspects to improve the country’s economic status. In particular, transportation is the crucial factor to the country’s economic growth. There are a variety of transportation types introduced in Malaysia, for example private vehicles (cars, motorcycles), public transports like monorail, commuters, LRT, MRT etc. The public transport choices have increased the convenience for many, especially working adults, but most Malaysians still highly depend on their own vehicles. This can be proven by the data from the Department of Road Transport (JPJ) Malaysia. According to JPJ, the total units of motor vehicles registered in Malaysia as of 31st December 2019 increased by 3.02 million, which is from 28.18 million to 31.2 million since mid-2017 (Lim, 2020).
Being someone who has lived in Kuala Lumpur (the busiest spot in Malaysia) for almost 11 years, I can confirm that one of the key topics among locals will be: TRAFFIC. But if you compare the number of registered vehicles, the human population in the country and the size of the country, it probably is not as surprising as it seems. Everywhere you go, you will hear people complaining about the complicated roads, paying tolls, and of course traffic jam. Indeed, traffic jam problems causes a waste of time, as many have noticed the most. However, people often neglect one more key issue due to heavy traffic, which is traffic noise.
What is traffic noise?
It is a noise generated by vehicles and the traffic volume. For the case of individual vehicles, the noise being generated is a combination of sounds from the engine, transmission, exhaust, tyres, air turbulence and the rattling of the vehicles’ body/load. Out of all these causes, the one that is the hardest to control would be tyre noise. This is because it does not only change with vehicle speed, it is also affected by the pavement type and road slope too. According to studies, at speeds between 30 – 50 km/hr, the tyre noise of a car can increase to a level which dominates the overall vehicle noise (Zaiton Haron, 2019).
As for traffic volume, there have been scientific research showing that by reducing 50% of traffic volume, the noise level can also reduce by 3 dBA. Heavy and large vehicles like trucks or buses highly contribute to the average noise level due to traffic.
How will traffic noise affect us?
According to the World Health Organization (WHO), traffic noise can lead to health issues like sleep problems, tiredness, headaches, stress, high blood pressure, or even an increased risk of heart disease. There are indications showing that children may have the risk of developing learning difficulties if exposed to constant/long-term environmental noise.
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|
(7.00 am – 10.00 pm)
(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.
The aspect about traffic noise should already be considered during the city planning stage, where the proper layout of roads, highways, buildings, commercial areas etc are included in the plan. For example, residential areas should not be located close to highways or main roads. Local authorities can apply zoning controls or land-use policies to limit the noise concentration at a certain area. Of course, the enforcement of vehicle noise emission limits is important too, for example setting permissible noise level for different vehicles so that the noise control can be implemented directly on the source itself, since prevention is better than cure.
Malaysia’s development in terms of transportation in the upcoming years is inevitable. As such, it is important to recognize the effect of traffic noise and implement effective measures or strategies to reduce noise pollution in the country, hence improving the living quality of the nation.
DOE, 2019. Guidelines for Environmental Noise Limits and Control, Putrajaya: Ministry of Energy, Science, Technology, Environment & Climate Change.
Lim, A., 2020. Vehicles registrations in Malaysia – 31.2 mil as of 2019. [Online]
Available at: https://bit.ly/31l95tW
[Accessed 16 October 2020].
Zaiton Haron, N. D. K. Y. H. H. A. N. M. M. A. H. Z. J., 2019. Review on Traffic Noise Problem in Malaysia. IOP Conf. Series: Earth and Environmental Science 220 012015, p. 13.
Written by Khei Yinn Seow
Posted on October 20, 2020