Pile ups happen because people drive: - Over the speed limit (it's called a limit for a reason) - Too fast for the conditions (speed limit != speed target) -

Pile ups happen because people drive: - Over the speed limit (it's called a limit for a reason) - Too fast for the conditions (speed limit != speed target) - Too close to the vehicle in front of them There are very few situations that can't be prevented by driving properly in the first place.