Reflex reflecting system for road surface marking

On a marked road roadway pavement, a traffic-regulating indicium including a layer of material having a upwardly facing surface the entire extent of which is approximately planar, wherein a substantial surface area of said surface includes a discrete number of reflective aggregates partially embedded in said layer, at least a part of said aggregates comprising each a substantially spherical transparent element having an exposed portion projecting upwardly of said surface and another portion projecting downwardly from said surface, said element having an index of refraction such that rays impinging said exposed portion at large angles of incidence are at least partially refracted into said element towards said another portion, and comprising further a layer of transparent binder substance outwardly surrounding said another portion of said element, and reflecting means for the reflection of rays refracted into said element associated with said other portion of said element and spaced from the same by said binder substance, provided that:

• a. said transparent element consists of a transparent polymeric substance the index of refraction (n.sub.1) of which is comprised between 1.45 and 1.68,
• b. said reflecting means consist of transparent beads partially embedded into said layer of binder substance and having a reflective coating on their part-spherical portions spaced from the associated element, said beads consisting of a transparent material the index of refraction (n.sub.3) of which is comprised between 1.60 and 1.95;
• and
• c. the ratio (n.sub.3 /n.sub.2) of the index of refraction (n.sub.3) of said beads relatively to the index of refraction (n.sub.2) of said binder substance is comprised between 1.135 and 1.385.