At What Speed Do Airbags Deploy (Explained)

If an accident occurs when a vehicle is at high speed, the damage level is usually higher, but you may be wondering – At What Speed Do Airbags Deploy?

There is no particular speed limit for airbag deployment, as they only deploy when an accident is likely to cause injury, which is determined by the degree of impact and the data sent to the airbag system by the crash sensor.

The article answers some questions you might have about airbags, such as at what speed do airbags deploy?. It also covers other related topics such as how an airbag works, what controls airbag deployment, and much more.

How Do Airbags Work?

The way an airbag works is not so complex. When a vehicle is involved in an accident, it stops immediately. However, objects inside the car do not stop moving immediately after the car stops.

The principle of inertia which is often called Newton’s first law of motion, explains why this happens. Thus, the body and everything in the car will continue moving forward at the same speed the car was moving until it collides with another object such as the seat belt or steering wheel.

The same sharp stop experienced by the body will also affect our body organs; these organs will also experience the same movement, which may result in serious damage to them.

Airbags work through sensors placed everywhere in the vehicle to detect a deceleration, similar to driving into a concrete wall at 10-15mph or above.

When this occurs, the airbag receives a signal which triggers a little explosion in the car.

This explosion swiftly releases inert gases such as argon or nitrogen into a nylon bag, making it pop. This is what can be seen whenever the airbag deploys.

Colliding with a surface that is not too hard will make the body stop at a very slow pace, reducing the likelihood of having a serious head or internal injuries, unlike a collision with a rigid surface.

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Types of Airbags

There are different types of airbags, and vehicles are equipped with different airbags depending on the vehicle manufacturer.

Generally, airbags are classified into these categories: knee airbags, frontal airbags, seatbelt airbags, and curtain airbags.

1. Frontal Airbags: These airbags are found either on the right side of the dashboard or the steering wheel. They activate moderately to reduce any injury that may result from near frontal or frontal collisions.
2. Knee Airbags: These airbags are found under the steering wheel and are there to prevent serious injuries to the legs and knees of the driver.
3. Side Curtain Airbags: For side curtain airbags, they are found across the car’s interior on both right and left sides.
4. Side Torso Airbags: These airbags usually extend from the right and left sides of the vehicle’s front seat.
5. Seatbelt Airbags: Tubular airbags can be found in some cars, which trigger from inside the seatbelt affected by a collision.

The collision determines which one of these airbags is triggered. For instance, in a frontal crash that occurs while the vehicle is on a low speed, the airbags close to the passenger’s front seat might be triggered.

If the collision is on the side of the car, the sensors may signal to activate the passenger’s side airbags instead of the knee airbags just below the steering wheel.

Airbags are activated based on the impact, and the crash sensor indicates what is sent to the airbag system to get it activated.

At What Speed Do Airbags Deploy in KM?

For an airbag to be activated, the vehicle must be moving at a speed between 13 and 23 km per hour at the time of the collision.

NHTSA defines this speed as the threshold for a “moderate to severe” near frontal or frontal crash.

This speed is also the normal speed for drivers that do not wear their seatbelts, while drivers that wear their seatbelts have their threshold raised a little bit more to a speed of about 16 mph, equivalent to 26 km/hr.

Do Airbags Deploy if the Car Is Not Moving?

The vehicle’s movement is not a prerequisite for the deployment of airbags. A vehicle not moving will still have its airbags activated if an entity moving at a speed between 16 – 28mph (equivalent to 26 – 45km/hr) hits such a vehicle.

However, this only happens when the car is stationary, but the engine is running, like at a red light or in a parking lot before you get out of it.

When a vehicle is stationary, and its engine is not running, the airbags cannot be activated if there is a collision.

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At What Speed Do Airbags Deploy in the UK?

Airbags are most times made to go off at the same speed as other parts of the world; hence the UK is no exception to this and has the same range as that of the US, which is from about 8 – 16 mph and above, which depends on if the driver using his seatbelts or not.)

At What Speed Do Airbags Deploy in Australia?

Front airbags in Australia are activated at a speed of about 8 -14 mph or faster, equivalent to 13 – 23 km/hr or more.

At What Speed Do Airbags Deploy in Canada?

Airbags Canada deploys if the effect of the collision is similar to crashing into a barrier at a speed of about 13 – 23 km/hr or more.

At What Speed Will Side Airbags Deploy?

The speed at which the side deploys is less than that of the front or near-front airbags. This is because if an object hits the vehicle from the side, it is likely to affect the passenger directly.

An instance is when a driver loses control of his vehicle and bumps into a tree, it is likely that the tree hits the driver directly, and the shattering glasses can also cause other injuries to the driver.

For this reason, side airbags are activated at a lower speed, like 8 mph, in a situation where the vehicle is driven into something not so large (like a tree or a pole.)

When the accident involves a larger part of the vehicle, like when the vehicle is hit from the side by another car, the threshold increases to about 18 mph (equivalent to 29 km/hr.)

Side airbags may be activated alongside the front airbags if frontal collisions occur at a speed good enough to deploy the frontal airbag. Although, this usually depends on the crash.

At What Speed Do Airbags Deploy in a Rear-End Collision?

Collisions from the back of a vehicle are different from other types of collisions in terms of injury potential.

If a vehicle gets bashed from behind, the airbag may not deploy because the most likely injury may come from whiplash, which the airbag cannot be too helpful in an instance like that.

If your vehicle hits another car from its rear, the front airbags will be triggered as it would be if it were a tree or wall that was hit and not a vehicle.

This implies that the car must be moving at a speed above the threshold of around 8 – 16 mph before hitting the other vehicle from the back before the airbags become active.

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Why Didn’t My Airbag Deploy?

Airbags fail to deploy for certain reasons; some of the reasons why airbags do not get activated include the following:

1. Severity of Crash

If the impact from a crash is moderate and not so serious, an airbag may not be required to protect the vehicle’s driver wearing a seatbelt.

Seatbelts usually provide adequate protection against injuries to the chest or head which a driver may be exposed to if he is not wearing his seatbelt.

2. Nature of the Collision

The nature of the accident is an important determinant in airbag activation. The part of the vehicle impacted indicates if an airbag will be activated rather than the speed or degree of damage sustained.

For instance, the frontal airbag will be deployed when the vehicle is involved in a moderate or severe collision affecting the front corners or bumpers of the vehicle.

The airbag sensors might not be triggered, depending on the part of the vehicle that was hit. This is because certain collisions, such as collisions from the side or the back of the vehicle, do not trigger frontal airbags.

3. Automatic Shut-off Sensors

The airbag systems have advanced over time. The airbag system automatically shuts the frontal airbag and a few side airbags on the passenger’s side if it detects that a child or person of small size is occupying the seat or that the seat is empty.

4. Defective Components

As with other vehicle parts, airbag sensors may fail to detect the impact accurately due to improper installation, testing, or software failure.

Damaged electrical parts or disconnected wiring may interrupt the collision signal connection between airbags and sensors.

Usually, this is the reason one airbag fails to deploy while another works fine. Faults in airbag modules could even stop airbags from deploying when they ought to, even when there is no disconnection in the transfer of signals.

5. Lack of Airbags

In Vehicles that have been used before, there is a possibility that after a crash, the airbag was not replaced. It is highly recommended that airbags be replaced every time they are deployed.

What Triggers Airbag Deployment?

Airbags usually have sensors that detect when a vehicle stops suddenly, and its speed is reduced significantly, which is usually the situation when an accident occurs.

Upon detecting an accident, chemicals burn due to an outburst that is triggered by an accident. This explosion blows up the airbag in split seconds.

Frequently Asked Questions – At What Speed Do Airbags Deploy

Conclusion – At What Speed Do Airbags Deploy

According to the National Highway Traffic Safety Administration (NHTSA), airbags are designed to deploy only during accidents in which you’re driving 8 to 16 mph (about 13 to 23 km/hr) or faster. This means that airbags won’t deploy if your car is stationary or you’re driving too slowly.

An airbag system in good working conditions might fail to deploy an airbag if the accident occurred at a speed less than the threshold.

This can also happen in situations like if a child occupies a front seat, when occupants have their seat belts on, or in a case where there was no airbag replacement after a prior accident.