Applied optics in the development of smart road markings

Road markings (RM) consist of two distinct layers: the paint layer and the retroreflective layer. Together, they function as system and are essential features for road safety. Recent studies have been centred on elevating these systems to a smarter level, imbuing them with novel functionalities, increasing their visibility, service life and road safety. These new capabilities encompass photoluminescence, anti-aging, selfcleaning, and thermochromism. The aim of this study is to review the advancements and highlight potential opportunities for RM, the materials employed, functionalization techniques, and the key outcomes achieved.