Abstract

The National Institute for Public Health and the Environment (RIVM) has determined new road traffic noise emission values. These values are needed to calculate road traffic noise levels at certain speeds. This information is used to produce noise maps of environmental noise caused by road traffic.

Noise maps are a European requirement and, as traffic volumes, road surfaces and built-up areas change, they are updated every five years. The noise maps are also used to evaluate policy on noise.

The update will result in calculated noise levels being 5 decibels lower on average in built-up areas, where vehicles travel at lower speeds. Noise levels are on average 1 decibel higher on motorways. The updated values ensure that calculated traffic noise levels more accurately reflect reality. This is because the amount of noise a vehicle makes can change over time, for example because vehicles become heavier or due to technological developments.

The new noise emission values are part of a calculation method that must be used to produce road traffic noise maps. This calculation method is described in Annex XXXIII of the Environmental Regulation and is also known as CNOSSOS. If the new noise emission values are incorporated in the Environmental Regulation with effect from 1 January 2027, they can be used to produce noise maps for the 2026 situation. The Minister of Infrastructure and Water Management (I&W) will take a decision on this.

Calculation methods are also available for other purposes in the Netherlands, such as housing development plans. These methods are described in other annexes to the Environmental Regulation. Emission values for these methods had already been updated, and were, therefore, already in use when the Environment Act came into force on 1 January 2024. If the Minister for Infrastructure and Water Management adopts the newly proposed emission values, the Dutch and European methods will use the same assumptions for road traffic noise.