Rainbow road sign film would be easier for autonomous vehicles to read

Even outside of fully autonomous vehicles, traffic sign recognition has been part of driver assistance systems for over a decade. Normally the technology is based on recognizing colors or shapes of signs, but it doesn’t always get it right in the real world, where readability can be affected by lighting, weather, obstacles, damage, or something as simple as stickers on the sign.

So for the new study a team of researchers investigated a promising new material that could make the job easier. It’s a new form of retroreflective material, already commonly used to highlight signs and road markings by bouncing light from a vehicle’s headlights straight back at a driver. But rather than focus that light, the new material scatters it to create eye-catching patterns.

It’s called a microscale concave interface (MCI) and is made up of a thin film of tiny polymer spheres embedded in tape.