I agree that kids do stupid things (that's exactly why I suggested the stuff about riding on sidewalks in my previous post), but so do adults. Almost every day on my short commute, I have to take quick action to avoid a collision. Just the other day, a young (20-25) woman came off the sidewalk riding straight out from behind a tree, on her way to cross the bike path on her bike. By the time she spotted me, I had already braked hard and almost stopped. She said "Sorry!" and I just mumbled "Yeah..." and continued. When such things happen to me, I often shout "Would you have done that if I had been a car?". Hopefully that makes them think about it a little bit. People are so used to bikes moving at 10-20 km/h, so that when I move at twice that speed or more, they can't seem to judge how much time they have until I pass them.

The most common stupidity, though, is people riding with earphones, making them completely oblivious to their surroundings. They just pedal along at 10-15 km/h, often moving back and forth across the bike path, blocking all faster traffic. Those who don't shut of their hearing with the damn earphones are just as bad at going in a straight line, but they hear me (for example) coming, and move to the side in time. Again, using the real street instead would allow me to stop worrying about all these people and just move! But alas, the law is the law, and I only break it when I think I could talk myself out of a ticket (there are some excuses that sometimes work).

I use Nokian 26x2.1" Extreme 294 for my winter riding and mostly Continental SportContact 1.3" or 1.6" the rest of the year. Not much difference between them on gravel. If anything, the Contis are more predictable, even if they do slide slightly more.