Automotive Academy

The speed of a vehicle is very important to the energy in a crash, even more important than the weight in the vehicle, when frontal and frontal offset crashes occur they are the most severe as they often happen when both vehicles are traveling at a high speed and in a opposite direction.

Rear and rear offset crashes often happen at lower speeds, and most of these cases are when one vehicle is stopped or nearly stopped, and another vehicle hits it from behind at a low speed.  Other cases of accidents like this are when both vehicles are traveling in the same direction at a similar speed and one is bumped from behind.

So the difference in the speed of the vehicles is usually much slower in a rear end crash, this means the energy in the crash will be much lower and if the energy is low there is less chance of a injury. Ride down time is the time is takes for a person to come to a complete stop in a crash. The total force on the passenger will increase with the weight of the person and the speed they were traveling before the crash. The total force on the passenger decreases as the time it takes to stop increases.

While we have often have no control of the speeds involved in a crash, we can do some things to help increase the time it takes for a passenger to come to a stop.  As mentioned earlier, in a frontal crash the vehicles are often traveling in opposite directions at high speeds.  When they crash, both vehicles stop very suddenly, in a small fraction of a second, and even a small increase in the stopping time can considerably reduce the risk of injury.