An innovative form of noise-reducing asphalt, known as drainage asphalt, has been tested for over a year on Denmark's Motorring 3, which is among the country's busiest highways. The Danish Road Directorate reports that this special asphalt has effectively reduced traffic noise by four decibels in the tested area.

This drainage asphalt was installed in the summer of 2024 along a six-kilometer stretch heading south from Frederikssundsvej to Holbækmotorvejen, passing through Rødovre, Glostrup, and Brøndby. The structure of this asphalt features greater gaps between stones and the surface layer, enabling it to function similarly to an acoustic ceiling, where the holes act to absorb sound. In addition to noise reduction, this asphalt is designed to facilitate quicker drainage of rainwater, which brings additional benefits during rain conditions, as highlighted in prior communications from the Road Directorate.

Motorring 3, approximately 17 kilometers long and closely bordered by residential areas, has been a focal point for noise reduction initiatives. With the installation of this special asphalt, the Danish authorities aim to improve the quality of life for residents living in proximity to the highway, addressing noise pollution while also enhancing road safety during wet weather. The combination of noise reduction and improved drainage capacity presents a forward-thinking approach to modern road construction and maintenance, aiming for both environmental and social benefits.