Why Dew Affects Traffic Sign Performance

Dew forms when air moisture condenses during cooler temperatures, typically at night or early morning. For most traffic signs, this results in droplets scattering light, reducing their retroreflectivity by 60%. Instead of guiding drivers, these signs become almost invisible in critical moments, increasing risks for road users, especially in low-light conditions.

How Does OL-1200 Work?

To understand how OL-1200 achieves its results, it helps to understand the difference between hydrophilic and hydrophobic surfaces:

• Hydrophobic surfaces repel water, causing dew to form in droplets that disrupt light reflection.
• Hydrophilic surfaces, like OL-1200, attract water evenly across the surface, forming a flat sheet that minimizes visual distortion.

Rather than scattering light, the thin sheet of water on OL-1200 allows light to pass through and reflect back uniformly, simulating the appearance of a dry sign.

Where OL-1200 Shines

To see the difference in results, look at this overhead guide sign on a highway in Turkey. During dew weather conditions, a sign with no overlay or just a standard overlay will lose retroreflectivity, making it difficult to read. The sign on the left retains its retroreflectivity and legibility because it was made with OL-1200.