Car horn standards will be applied in vehicle registration from 2025.

The specific regulations on vehicle horns aim to enhance traffic safety, ensuring that the horn system on vehicles meets the requirements for volume and stability. Accordingly, the inspector will check the horn by pressing the horn and observing and listening to the sound emitted. Evaluation criteria include that the sound must be emitted continuously, with stable volume, and the horn must be installed in the correct position and operate normally.

If there is any doubt about the volume of the horn (too low or too high), the inspector will use a sound level meter to determine. The microphone of the measuring device will be placed at a distance of 7m from the front of the vehicle, with a height of between 0.5m and 1.5m above the ground. The sound level measurement result must be between 87 dB(A) and 112 dB(A), to ensure that the sound is strong enough to warn but does not cause noise pollution.

From 2025 there may be a new set of inspection criteria.

In addition to the regulations on horns, the draft also mentions the control of noise levels of automobile engines. If the noise emitted from the vehicle exceeds the allowable threshold, the inspector will measure the noise level at the tail of the exhaust pipe according to TCVN 7880 standard. To ensure quietness in the traffic environment, the noise limits after calibration are given based on each type of vehicle.

Specifically, cars, light trucks, light passenger cars and vehicles with a total mass of less than 3,500 kg must ensure that the noise level does not exceed 103 dB(A). Meanwhile, heavy vehicles with a mass of over 3,500 kg and engines with a capacity of less than 150 kW will be allowed to emit sound of no more than 105 dB(A). For vehicles with larger engine capacity, the limit is 107 dB(A). Special motor vehicles such as cranes will have the highest noise threshold of 110 dB(A).

The application of this national technical regulation from 2025 will not only help improve vehicle inspection quality but also contribute to improving traffic safety and reducing noise pollution caused by vehicles.

At the same time, this is also a measure to ensure that vehicles participating in traffic must have standard horns and sound systems, helping drivers use the horns for the right purposes, avoiding abuse or using horns too loudly, causing inconvenience to other road users.

Source: https://www.congluan.vn/quy-chuan-coi-oto-se-duoc-ap-dung-trong-dang-kiem-tu-nam-2025-post312428.html