Red asphalt overlays safe for cyclists

Katwijk municipality applies red asphalt overlays in its road area as an attention-raising measure at intersections and in 30-km zones. In 2023, there were suddenly several reports that cyclists, especially when the road surface was wet, were falling on these relatively young surface layers. The skid resistance of the surface layers was measured using the Pendulum Test and RAW Test 72 for 'wet skid resistance' and tested against the available requirements for intervention. This quantitatively established that the surface layers were too slippery for cyclists.

On the basis of research into the skid resistance properties of crushed stone (mixtures), the so-called PSV value, and laboratory research (Friction After Polishing, FAP test) into the long-term skid resistance properties of various mixture variants. This research resulted in new standard coloured asphalt mixture with a demonstrable service life expectancy of more than ten years.