A lot depends on where the road is located. Last year, they repaved a lot of the road at Mt. Rainier National Park, here in Washington State. The section from Longmire up to Paradise was brand new. It is very twisty, and in many spots the drop off is several hundred feet or more. I got about three miles up and said "F___ this!"
It was raining (big surprise) and I was noticing some kind of brownish foam at the edges of the asphalt, and in the ditches. The road was so new, it was the first time it had been rained on, and the water was washing oil out of it. Slicker than deer guts on a doorknob. I stopped in a parking area and did a slow-speed brake test, and there was almost no pressure before the ABS kicked in. My boots had no traction. My rear tire was sliding out on some of the turns at about 10 MPH.
I was about to go back onto the road to head down and a guy heading down on a bicycle came into the parking area, and we talked. He was scared to death, his skinny tires had NO grip and he said it was like riding on ice. I'm a long-time bicyclist so I know that feeling. We went back down sort of together, at about 5 MPH. Made it OK, but it was the scariest I've encountered.
2007 ABS Wee-Strom "The Silver Surfer"
2003 Kawasaki Concours "Mabel, the Flying Kaw"