Glow-in-the-dark road lines are a sort of road marking that shines in low-light settings, increasing visibility for drivers at night or in inclement weather. These lines are often formed from photoluminescent materials, which collect sunlight during the day and emit light at night. The concept aims to improve road safety by offering greater information to drivers, eliminating the need for street lighting in some regions, and encouraging energy economy.

The science behind glow-in-the-dark road markings is based on photoluminescence principles, specifically the usage of photoluminescent pigments. These pigments contain phosphorescent elements, which absorb energy from a light source (usually sunlight) during the day and re-emit it as visible light at night.

Photoluminescence Process:

Absorption: During the day, photoluminescent pigments absorb photons, which cause electrons within the material to become more energetic.

Storage: Once stimulated, electrons remain in a higher energy state and store the energy. The period of storage is determined by the material’s chemical characteristics.

Emission: In the dark, electrons gradually return to their original, lower energy state, releasing stored energy as visible light. This emission occurs over time, which is why the road lines continue to light several hours after sunset.

Materials Used:

Strontium aluminate is the most prevalent photoluminescent pigment in current applications. Strontium aluminate is highly efficient, producing a significantly brighter and longer-lasting glow than previous materials such as zinc sulphide.

Pigment Binders: To be used as road lines, these pigments are blended with long-lasting binders (such as epoxy or polyurethane) that stick effectively to road surfaces and can survive traffic wear and tear.