When I was first taught how to drive the very first lesson my father imparted to me was simple, "Assume everyone else on the road is an idiot who could kill you."
Some people may consider such advice a little too cynical but in terms of being able to avoid accidents by always being able to see them coming, it's certainly advice that's paid off for me. It could have also helped these people who ran into a driver (some are arguing a 14 year old was driving at the time) who missed their exit on a highway and decided to back up in order to reach it. Many cars swerve out of the way but not all as a huge wreck is eventually caused.