We might think we know everything there is to know about it, and yet… It’s not a luxury to remind ourselves why a seatbelt, properly worn, is so important!

A crucial role
Everyone knows that seatbelts are there is to protect us, and others, from the impact of a collision: more precisely, a seatbelt keeps a driver or passenger from striking parts of the vehicle interior, or two occupants from striking each other.

In a collision, a vehicle’s occupants continue to travel, for a few tenths of a second, at the same speed the vehicle was going before the collision. It is at that initial speed that people slam into parts of the passenger compartment, or into each other, if they are not safely belted in. In other words, drivers and passengers not wearing seatbelts become projectiles in a collision; the violent impacts resulting in such circumstances cause serious injuries. In some cases, passengers may even be thrown with enough force to eject them from the vehicle. In short, wearing a seatbelt protects us from impacts with objects in the vehicle and other occupants in a collision.

Moreover, in vehicles equipped with airbags, it is all the more important to wear seatbelts: by keeping the occupants in their seats (and properly positioned), seatbelts maximize the benefits of the airbag. Seatbelts also help slow the passenger’s forward motion toward an inflating airbag, helping the device do its job properly.


A matter of weight
Some people may believe they are strong enough to protect themselves or a child in an accident, without the benefit of a seatbelt. The following fact should dispel that belief: in a 50 km/h collision, the force of impact is 20 times the mass of the individual projected, as shown in the table below.

FORCE OF IMPACT IN A 50 km/h COLLISION

PASSENGER WEIGHTFORCE OF IMPACT
4 kg (9 lb)80 kg (175 lb)
9 kg (20 lb) 180 kg (397 lb) 
18 kg (40 lb)360 kg (794 lb)
25 kg (55 lb)500 kg (1,100 lb)
50 kg (110 lb)1,000 kg (2,200 lb);
75 kg (165 lb) 1,500 kg (3,310 lb)
100 kg (220 lb)2,000 kg (4,410 lb)

Looking at these figures, it’s easy to see that no vehicle occupant would be able to hold on to another in a collision, even if they were wearing a seatbelt themselves. And if they aren’t belted in, there is the additional danger of crushing a child or even an adult under their weight.


Wear it well
Wearing a seatbelt is one thing; it’s just as important to wear it properly:

  • The lap part of the belt must fit snugly across the hips, not the abdomen.
  • The shoulder strap must lie against the collarbone, not the neck.


Note: The shoulder strap of a three-point restraint system must never be worn under the arm. In an especially brutal collision, the strap would exert pressure on the ribcage, possibly even severing the aorta, the main artery leading to the heart.

  • The belt must also remain taut to do its job properly.

Lastly, for a pregnant driver or passenger, the proper way to wear a seatbelt is sitting upright, with the lap belt below the abdomen, as low across the hips as possible, and the shoulder strap, slightly loosened, running across the chest.