Abstract
Velocity and vehicle type affect traffic noise. The maximum noise level permitted should be internationally lowered. Wet road surfaces, slopes, surrounding buildings and crossings with traffic lights cause more noise. Radial tyre and rough road surfaces promote safety, but produce more noise. Overgrowth and porous materials can diminish the south level. The concept law on noise, by which sound zones are established alongside the roads, is described. For the second and third article on the same subject see B 14894 and 14895.