I just did my first 70 mile ride of the season last weekend on a bike with Gatorskins. Just a few miles from home I was cruising along at a brisk pace on a busy road, and suddenly saw the bike lane was *covered* in broken glass. Imagine a gravel path, but the gravel is entirely crushed glass. There was too much traffic to swing out of the lane, and I was going to fast to brake before running into it, and I really didn't want to brake hard on a loose surface, so I plowed right through it. It extended for perhaps 20 yards. By the end, I slowed down, pulled over, and checked the tires for embedded glass, and...YIKES! I had cords showing through the rear tire, but no embedded glass.
The bike got a new tire as soon as I got home.