My experience is that it is usually the faster groups coming up behind a slower disorganized group that ends up involved in the worst crashes. Either the folks at the front don't communicate well with the people behind them and when they slow down, nobody has room to maneuver. Or somebody in the slower group swerves out unexpectedly and causes chaos behind them as people try to avoid them. Communication is the key to avoiding either scenario.


Also, trust the hairs on the back of your neck. If you are riding in a decent sized group and coming up fast on a group of slower riders that look a bit disorganized, pay attention to that little voice saying "this could get dangerous". Give yourself a little more room in front of you and plan an escape path or two in case things go south ahead of you.