Measurements by RIVM show that motorways again produced more noise in 2020 than the Directorate-General for Public Works and Water Management had calculated. The difference was 3 dB, the same as in 2019. Due to the coronavirus measures and the speed limit reduction, however, the noise levels along both motorways were lower in 2020 than in 2019. This is according to the 2021 Noise Monitor. The figures also show that, in 2020, so-called ‘quiet tyres’ still do not reduce noise produced by motorways in practice. The measurement and calculation of noise produced by railways did match.

Difference between measurement and calculation due to ‘quiet tyres’

The 2021 Noise Monitor shows that the noise level from cars has not declined since the introduction of quieter tyres in 2016. However, the calculation by the Directorate-General for Public Works and Water Management assumes such a decrease. This results in a difference of 1–2 dB. The difference can additionally be explained in part by the fact that the road sections at the measurement locations have older asphalt than most other roads in the Netherlands. Older asphalt produces more noise.

Deduction for quiet tyres to be abolished

Based on the conclusions of the Noise Monitor, the Ministry of Infrastructure and Water Management has decided that the deduction for quiet tyres will be removed from the Environmental Regulation (Omgevingsregeling) by 1 October 2022. As soon as the Environmental and Planning Act (Omgevingswet) enters into force, the effect of quiet tyres will no longer be taken into account in noise calculations. This will largely remove the difference.

What is the Noise Monitor?

Every year, RIVM uses the Noise Monitor to check whether the calculated and measured noise levels along railways and motorways match, as is its statutory duty under the Environmental Management Act (Wet milieubeheer). Where necessary, this information can be used to amend regulations.