Reflective Glass Beads for Pavement Markings
Retroreflective highway signs and lane markers use special kinds of paints and materials. Most retroreflective paints and other pavement marking materials (PMM) contain many thousands of glass beads per square foot that are bonded to the highway with a strong binder. Instead of scattering light, as normal paints do, retroreflective paints containing glass beads turn the light around and send it back in the direction of your headlights. Figure 3 portrays how glass beads perform retroreflection.
This excerpt is taken from the RoadVista Guide to Retroreflectivity, for additional information download the free RoadVista Retroreflectivity Guidebook