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Enforcement with Acoustic Cameras Effective from 2021

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The EPA announced that, from 1 January 2021, acoustic camera technology will start to be deployed to increase the efficiency of law enforcement for cracking down on high-noise vehicles. Vehicles with noise levels exceeding standards will be directly fined on the spot. With all detection systems triply certified and a two-step quality control mechanism for processing violations, all high-noise vehicles that violate noise standards will be caught red-handed in real time, unable to hide their transgressions from the cameras.


To clamp down on high-noise vehicles, the EPA currently conducts roadside inspections or notifies vehicle owners to go to specific locations to measure stationary noise levels. However, measuring stationary noise can only primarily deal with noise problems caused by improperly modified vehicles; there are cases where noise that vehicles make are loud on the road but are within standards when the vehicles are stationary. This is due to improper driving behaviors of drivers on the road. In light of such scenarios, the EPA referenced the law enforcement model with speed cameras, and has been working on penalizing violators directly on the spot using acoustic camera technology. To have laws to base the penalties on, the EPA has completed the revision or formulations of three laws: Methods for Measuring Motor Vehicle Driving Noise Image-assisted Method was announced on 15 October 2020, and the revised Motor Vehicle Noise Control Standards and the revised Regulations Governing In-Use Motor Vehicle Noise Control were announced jointly with the Ministry of Transportation and Communications (MOTC) on 1 December 2020.

The EPA pointed out that, to ensure the fairness and objectivity of the acoustic camera systems, it has referenced the experiences of using the interval speed detection systems and require all hardware used for the acoustic camera systems to be triply certified. In addition, it has also instituted a two-step process for verifying violations to ensure the credibility of law enforcement.

1. Triple equipment certifications: Sound level meters need to be certified by the Bureau of Standards, Metrology and Inspection (BSMI) and should be approved every two years; the acoustic camera systems are required to pass the EPAs comparison tests, and; all hardware is to be calibrated every three days and time-synchronized every five minutes.

2. Two-step process for verifying violations: When a violation occurs, background disturbances are to be removed first (background noise should be adjusted for and weather data such as wind speed or rain should be checked), and other sources of sound are to be clarified (video and audio clips recorded three seconds before and after the incident should be kept to verify the sources of noise).

As for public concern about too few acoustic cameras being deployed, the EPA noted that the purpose of law enforcement via such technology is to detect noise violations, and to maximize equipment efficiency, precise enforcement will be carried out in the future. This means road sections with frequent noise complaints will be prioritized for the installation of fixed surveillance equipment for long-term noise monitoring, while mobile surveillance equipment will be used at times and locations that have frequent complaints.

Excerpt from Major Environmental Policies, Dec 2020
Ministry of Environment