Solar road studs are flashing solar cell powered LED maintenance-free lighting devices used in road construction to delineate road edges and center lines. Embedded in the road surface, they are an electronic improvement on the traditional cat’s eyes in that they may give drivers more than a thirty-second reaction window compared with about 3 seconds for conventional reflective devices. The intense brightness of the LED’s makes them easily visible at distances of about 900m under favorable conditions.
Averaging about 100mm square or 100mm diameter and about 40mm thick, units are extremely robust to avoid damage by passing vehicles, and are normally constructed of engineering plastics and poly carbonates. Use of solar road studs reduces the necessity of headlight main beams and the accompanying hazard of dazzling oncoming drivers. They are also more visible in rain and fog conditions where the old type retro reflectors and road markings are problematic. The solar cells charge batteries or capacitors during sunlit hours, over which period the flashing LED’s are turned off by a photo switch.