My only crash of any consequence while touring occurred when I was riding with a group that I was not familiar with and they refused to use loud audible signals like "slowing", "stopping", or "turning" even when the group was tightly spaced. Low hand signals when carrying panniers doesn't cut it. It was inevitable then that this one woman took a couple of us out when she decided at the last second to take a quick right turn into a driveway without letting anyone know her intentions, guess she thought we were mind readers. After that, I either rode at the very front if I knew where we were going or I rode well off the back.