It didn't turn out bad, just exciting. However, the potential was there for a really nasty situation.

My wife and I were cycling through Yellowstone NP on our way east when we came upon a traffic jam. The cause of the jam was a buffalo grazing between the road and a sheer rock cliff on our side of the road. Everyone had to stop and take a picture. There was only about 10' between the edge of the road and the cliff. We decided to go around the cars and trucks on the outside rather than between the vehicles and the animal. We were riding about 8-10 feet apart, and I was in the back. We had a large pickup truck between us and the animal as we approached the buffalo. We thought this was a good idea. However, just when my wife was at the bed of the pickup the driver gunned the engine and screeched out. This panicked the animal, and it bolted across the road right between my wife and me. Luckily, we were going slow enough that it squeezed through with no contact. They may look slow, but I can attest to their speed and agility. However, I believe they look much larger up close than they really are.

This is one of the few times on a bike tour that I didn't get a picture.

IMO-The "ten worst" things listed by the OP just come with the turf, and he does a good job of pointing this out. If you bike tour you just deal with them. In climbing we call the things that you can't control "objective" hazards, and accept them as part of the activity. The "subjective" hazards are things within our control and can be dealt with by skill and experience. The point is: we control the things we can, and learn to deal with the rest.