SPEED REDUCTION DOES NOT CUT IT IF WE WANT TO ELIMINATE TRAFFIC NOISE

10.08.2023

By Peter Hostrup Rasmussen, COWI.

Road surfaces, noise screens and speed regulation are short-term solutions to problems with traffic noise. To eliminate traffic noise, we need to take a comprehensive approach and broaden our palette of solutions. 

Traffic noise has taken up a lot of space in the media in recently. And for good reason. Noise caused by traffic affects many more than the residents closest to busy roads. Noise may have several adverse health effects, ranging from headaches, sleeping disorders and stress to high blood pressure and risk of heart disease, according to a WHO report.

Significant speed reductions are tangible measures that will make a real difference to people living in areas afflicted by noise. This is but one of several solutions that should be implemented if we want to eliminate traffic noise. Another widespread solution is noise screens, but we need to look at the cause of the problem, i.e., the noise.

The main source of traffic noise is the interaction between tyres and the road surface, usually asphalt. And whereas we have long turned to different types of road surfacing to reduce noise, we have yet to impose any severe requirements on tyre manufacturers and, in reality, on car manufacturers.

Road surfaces, noise screens and speed regulation are short-term solutions to problems with traffic noise. To eliminate traffic noise, we need to take a comprehensive approach and broaden our palette of solutions.

NOISE REQUIREMENTS FOR REHABILITATION OF EXISTING INFRASTRUCTURE

A scenario where all motorways are covered or cars are only allowed to go by 70 or 80 km/h is unrealistic. So, we need to implement requirements and regulations, in addition to short-term solutions, to get long-term effects. Not least, this would affect tyre and car manufacturers, which could be included in collaborations on solutions that address the actual noise source. 

Indeed, there is a tyre labelling scheme that aims to provide EU citizens with a better decision-making basis when buying tyres. One of the parameters included in the scheme is how much noise the tyres generate outside the driver's compartment (external noise). It may prove necessary to set higher minimum requirements, and history has shown that when manufacturers face requirements, the industry is both ready for reorganisation and interested in contributing to a positive change. 

Another avenue we have to explore to reduce traffic noise is existing infrastructure projects. When we build new infrastructure, a number of requirements must be met, also in terms of future noise. These requirements do not apply to expanding or rehabilitating existing infrastructure. 

Nonetheless, it would be an obvious next step to integrate traffic noise into the equation when dealing with any type of infrastructure project, including rehabilitation or expansion jobs. 

So, we encourage everyone to combine both short-term and long-term solutions in order to identify the best overall solutions that effectively reduce noise levels on and along our major roads. 

By Peter Hostrup Rasmussen, COWI
Brought as op-ed in Danish news media Altinget