Audi Q5: Why use safety belts?

Frontal collisions and the law of physics

Frontal crashes create very strong forces for people riding in vehicles.

Fig. 155 Unbelted occupants in a vehicle heading for a wall

Fig. 156 The vehicle crashes into the wall

The physical principles are simple. Both the vehicle and the passengers possess energy which varies with vehicle speed and body weight. Engineers call this energy "kinetic energy." The higher the speed of the vehicle and the greater the vehicle's weight, the more energy that has to be "absorbed" in the crash.

Vehicle speed is the most significant factor. If the speed doubles from 15 to 30 mph (25 to 50 km/h), the energy increases 4 times!

Because the passengers of this vehicle are not using safety belts they will keep moving at the same speed the vehicle was moving just before the crash, until something stops them - here, the wall > fig. 156.

The same principles apply to people sitting in a vehicle that is involved in a frontal collision. Even at city speeds of 20 to 30 mph (30 to 50 km/h), the forces acting on the body can reach one ton (2,000 lbs. or 1,000 kg) or more. At greater speeds, these forces are even higher.

People who do not use safety belts are also not attached to their vehicle. In a frontal collision they will also keep moving forward at the speed their vehicle was travelling just before the crash, Of course, the laws of physics don't just apply to frontal collisions, they determine what happens in all kinds of accidents and collisions.

What happens to occupants not wearing safety belts?

In crashes unbelted occupants cannot stop themselves from flying forward and being injured or killed. Always wear your safety belts!

Fig. 157 A driver not wearing a safety belt is violently thrown forward

Fig. 158 A rear passenger not wearing a safety belt will fly forward and strike the driver

Unbelted occupants are not able to resist the tremendous forces of impact by holding tight or bracing themselves. Without the benefit of safety restraint systems, the unrestrained occupant will slam violently into the steering wheel, instrument panel, windshield, or whatever else is in the way > fig. 157. This impact with the vehicle interior has all the energy they had just before the crash.

Never rely on airbags alone for protection. Even when they deploy, airbags provide only additional protection. Airbags are not supposed to deploy in all kinds of accidents. Although your Audi is equipped with airbags, all vehicle occupants, including the driver, must wear safety belts correctly in order to minimize the risk of severe injury or death in a crash.

Remember too, that airbags will deploy only once and that your safety belts are always there to offer protection in those accidents in which airbags are not supposed to deploy or when they have already deployed. Unbelted occupants can also be thrown out of the vehicle where even more severe or fatal injuries can occur.

It is also important for the rear passengers to wear safety belts correctly. Unbelted passengers in the rear seats endanger not only themselves but also the driver and other passengers > fig. 158. In a frontal collision they will be thrown forward violently, where they can hit and injure the driver and/or front seat passenger.

READ NEXT: