Abstract
A new concept for open graded asphalt named TWINLAY, a porous double layer of rubberized asphalt with a base layer from course, and a thin top layer from small chippings is presented and discussed. Traffic noise measurements on a test track have been carried out. This showed a high level of noise reduction in comparison with dense asphalt concrete. The combination of the two layers seems to give an extra advantage in noise reduction especially at moderate vehicle velocities.