Horizontal road markings with high retroreflectivity: durability, environmental, and financial considerations

Horizontal road markings are critical road safety features, which must be reflectorised with glass beads to be effective during night-time driving. Road trials demonstrated that durability of thin-layer road marking systems depends primarily on the selection of paint and is strongly influenced by the choice of glass beads. With the use of premium glass beads, initial retroreflectivity (RL) exceeding 500 mcd/m²/lx was easily achieved. Road trial in Croatia demonstrated that road marking systems based on high-end modern solutions (waterborne high-performance paint reflectorised with premium glass beads) can last over two years and provide RL over 300 mcd/m²/lx. However, the most durable system tested in Poland failed within one year, because of severe damage caused by extensive winter maintenance. Analysis of financial and ecological aspects has shown that the worst choice is the use of road marking systems with low durability, requiring semi-annual renewal. Premium systems were calculated to be the most expensive, but simultaneously were found to be most durable; hence, their long-term cost may be lesser despite higher initial expense. High retroreflectivity of such systems, exceeding the existing norms, is expected to improve road safety.