Function of safety devices and correct method of use

Air bags

The operation and effects of air bags

Air bags equipped in passenger cars in Japan are called SRS(Supplemental Restraint System) air bags, and are used in conjunction with seatbelts to supplement the functions of the belt upon collision to reduce the impact on the passenger.
Air bags instantly inflate upon frontal collisions to prevent the passenger from direct contact with the steering wheel or instrument panel to reduce the impact to the head and chest.

Effective range of air bags

Air bags that are currently used in Japan are designed to inflate upon frontal collisions in accordance with the conditions defined by the manufacturer, with the purpose to supplement the performance of the seatbelt to prevent any serious injuries to the occupant. Therefore, the air bag may not inflate depending on the collision angle, collision speed or collision obstacle, and on the other hand, the air bag may inflate even though there is no collision taking place, such as instances when the vehicle drives over a curb or in similar instances when the sensor detects a shock exceeding a certain level.
The following are the general conditions when the air bag inflates and when it doesn't inflate. Note that air bags are not effective in secondary collisions, because they immediately deflate after fully inflating.


(1)Conditions under which air bags inflate
(1)Upon frontal collision with a solid structure such as a concrete wall at speeds faster than 20-30 km/h
(2)Upon collision with an automobile and when exposed to an impact similar to that described in (1) above.

(2)Examples of conditions under which the air bag may not inflate

(1) Collision where there are extreme deformations, where only one portion of the front of the car is deformed as when colliding with a telephone pole. (2)Collisions where the impact is gradual as when driving under the load space of a truck.


(3)Collision where the collision barrier is greatly deformed or relocated as in cases of side impact with a passenger car. (4) Collision where the impact direction is dispersed or the vehicle greatly moves while colliding as in cases of oblique impacts.

Usage precautions for vehicles equipped with air bags

Air bags are not fully effective unless seatbelts are properly worn. The death rate was roughly about 15 times greater when the air bag activated while seatbelts were not worn. Always fasten your seatbelt for the best performance form your air bag.
If you don't wear your seatbelt properly, there is a danger of considerable injury from the air bag. Wearing the seatbelt as shown in the figures below is dangerous.


(Institute for Traffic Accident Research and Data Analysis)

Risk of air bag injuries

Air bags are designed to be effective during high-speed collisions and reach an inflation speed of 100-300 km/h. For this reason, a passenger may be injured with abrasions (welted scratching), contusions (bruising), bone fractures, burns and other injuries when the air bag inflates.
There is also a greater risk of injuries if the seatbelt is not used or if other warnings are not properly observed. The gas generated when the bag inflates is not especially toxic.

1.Is it necessary to fasten seatbelts, even when air bags are equipped?

An air bag is a device that supplements the seatbelt function. If you do not wear seatbelts, there is a danger that the air bag could have little effect, or worse, could cause considerable injury.

2.Is it true that a danger of air bags to shortstature individuals has been announced in the United States?

In the United States, there have been accidents in which short-stature individuals have been injured by the impact of the air bag, due to such factors as the improper wearing of seatbelts. Thus, you should wear your seatbelt and position yourself correctly, not too close to the steering wheel.

3.When I was driving a car equipped with an air bag. I had a frontal collision and was injured by the air bag that inflated.

Air bags are designed and mounted in vehicles so that passengers will not suffer fatal injuries in a frontal collision and a certain high-speed collision is taken into consideration to determine the inflation timing and inflation speed.
Therefore, air bags may not completely prevent any injury in all types of frontal collision.

The operation and effects of side air bags


Side air bags inflate instantaneously in the event of a lateral collision to reduce the impact force on the chest and other upper body regions. Just as with the air bag during frontal collision, occupants who are not wearing seatbelts face the danger that the side air bag could have little effect, or worse, could cause considerable injury. And, given that they inflate only in response to a lateral collision and then quickly deflate, they are not effective in accidents such as frontal collision, rear impacts, multiple collisions, rollovers, and spills.
Recently, side curtain air bags (SCA) which inflate instantly covering all of the side window in the event of side collision to soften impact on the head against piller, side glass or outside vehicle body have been developed.

Usage precautions for vehicles equipped with side air bags

Side air bags are not a substitute for seatbelts. You should position yourself correctly in the vehicle and be sure to fasten your seatbelt. If you don't wear a seatbelt, there is a danger that considerable injury may be caused by the air bag. It is often the case that side air bags are installed in the seatback, making certain actions including those in the figures below dangerous.
You should use only specially designed seat covers, otherwise there is a risk that side air bags will not inflate properly.
Do not lean on the door or place your arm around the seatback, as there is a danger of considerable injury when the side air baginflates.

You should use only specially designed seat covers,
otherwise there is a risk that side air bags will not inflate properly.
Do not lean on the door or place your arm around the seatback,
as there is a danger of considerable injury when the side air bag inflates.