Reginald Lane, NC-E Chapter Educator
How long do you think it takes for the asphalt to lose its "new" properties?
When do you know it is safe to actually lean and not risk to slip?
When does it become “normal"?
- On fresh asphalt/blacktop take it easy on the turns as long as it’s that dark new color. You can tell blacktop that is new versus blacktop that is a few weeks older, the darkness of it starts to fade when it is fully dry.
- Asphalt gets an oil sheen on top that can cause slipperiness until after it cools (usually a couple of days), then a good rain washes it away.
- Asphalt has oil in it and even after it dries, you should wait for a good rain before you consider it "normal" or broken in. Even on older asphalt I'm super careful, until they're fully broken in I'll continue to be extra careful.
- Even asphalt a couple of months old can become slick again on a VERY hot day...like above 100 F. When it cools a bit, the sheen is still on the top. It may not be evident until the beginning of the next rain.
- Unless it is so old that it looks like concrete, slow down on asphalt at the beginning of a rain. Even if the main pavement is not slick, other things can be—like the tar snakes and painted lines—and the middle of the lane approaching a stop.
- Surface material matters very little. It is the texture of the surface that matters. If the surface is smooth, it is likely to be very slick in the rain.
- I was amazed when I read an article in one of the bike mags about how much the formula for laying blacktop varies, especially according to ambient temperatures and solidity of the local surface. They can also vary grip levels, giving a grippier surface at (for example) a road junction than along a dead straight stretch of road.
- But there's an easy answer to the dilemma. With new asphalt or very hot asphalt, we should apply the old maxim "if in doubt, slow down.” Just assume it's slick. If you assume it's not slick, and it really is, you're much worse off than if you HAD assumed it was slick, even if it really wasn’t. Better to be late in this life than early in the next.