Noise Emission of Structured Road Markings

Road markings with a structured surface like regular patterns or a random texture have an increased nighttime visibility under wet conditions. In contrast to this advantage structured road markings show an increased noise emission when they are overrun by vehicle wheels. On a test field a choice of different structured road markings as well as a flat road marking were analyzed regarding the noise emission at different velocities of a passenger car. In a speed range from 30 to 120 km/h the controlled pass-by noise of the car was measured. Beside the A-weighted sound pressure level the third octave spectrum was calculated and the vertical directivity was analyzed. Against the background of these results the application area of the different structured road markings can be concretized in order that the positive photometric effects or the intended rumble can be used furthermore without annoying residents.