Two friends of mine, Al Mattson and Paul Michelin, shared a recent experience they had when out with a buddy enjoying the twisties. All highly experienced and skilled riders, Al and Paul made it safely through a right-hand curve only to discover their friend had not. He and his bike slid mid curve, regained traction and then shot across the oncoming lane and over an embankment. Amazingly, neither man nor motorcycle was harmed in the making of this lesson. After recovering the bike and calming nerves, the three went to the corner to investigate. Near the freshly painted white fog line they found a long field of loose particles. Although the rider avoided touching the painted line with his tires, he lost traction on the fine debris near the line. Why?
What gives striping its reflective qualities is an abundance of small glass beads that are mixed into the paint. Many road paints are water based and silicone is added to speed drying and extend wear, all contributing to slipperiness (particularly when wet or damp). When the lines are sprayed, especially on a windy day, overspray puts loose particles of paint—including those tiny glass beads—onto the road surface adjacent to the stripe, where they become mini ball bearings to a rider, even on a warm, dry day.
If road striping looks fresh, put more space between your tires and the painted lines. Keep speed and lean angles conservative (hard to do when a fresh road surface begs the rider to pick up the pace). And keep an eye out for those dangerous spots where vehicles have driven through when paint was wet and spread the slippery stuff into the lane. I know Al, Paul and their buddy will do so from now on!