Follow The Three Second Rule!
Rear end collisions are one of the most frequent crash types, but if you follow the Three Second Rule you will greatly decrease your chances of rear ending someone.
Simply leave 3 seconds worth of room between you and the vehicle you are following. Just watch the vehicle in front of you pass a road sign or other inanimate object on the side of the road and count out “One Massachusetts, Two Massachusetts, Three Massachusetts” before your vehicle passes that same object. In most situations, this will provide you sufficient distance to react and stop if the vehicle in front of you slows or stops suddenly. When conditions are not ideal (snow/ice, heavy rains or driving a heavy vehicle…even if it’s just full of people) give yourself 4, 5 or even more seconds of space.
Avoid the old adage of keeping one car length for every ten miles per hour you are traveling. Unfortunately, that never allowed for enough room (vehicles take much further to stop the faster they are going) and required you to make special judgements while moving that complicate things even more.
Following the Three Second Rule will drastically reduce your chances of crashing as well as the severity of a rear end collision. It also helps reduce road rage related to tailgating.