There are no laws mandating that semi trucks be equipped with airbags; however, some trucking companies may choose to install them anyway.
Airbags protect drivers in front-end accidents from having their heads struck against dashboard and steering wheels, and are designed to deploy within 55 milliseconds when activated by their ignitor’s gas release mechanism.
Beginning as an initiative of law, all new light trucks were mandated by 1998 to include front driver and passenger airbags.
Front airbags, which are stored in the steering wheel or dashboard and deployed when the vehicle crashes, protect both drivers and passengers by covering their head and torso areas as well as helping prevent seat belt ejection during collisions.
Airbag deployment and inflation takes approximately 0.04 seconds after an impact, although they don’t provide adequate protection in side, rear, or rollover collisions.
Linderer received a patent in 1951 for an airbag system using compressed air to inflate it; Hetrick received one for an “automotive safety cushion assembly,” using explosive devices instead to initiate airbag inflation. Linderer’s invention saved many lives while injuring or killing some front passengers; manufacturers then developed an improved airbag known as Advanced Frontal Airbag (AFAB), now standard on many vehicles.
Even though front airbags are now required on all new trucks, side airbags are still optional or standard on higher trim models due to their ability to reduce injuries in side crashes and save lives during side crash tests conducted by organizations like Insurance Institute for Highway Safety (IIHS). They’re also essential in protecting head impact injuries when performing side crash tests conducted by IIHS.
IIHS tests include simulating a collision involving a dummy crashing into the side of a vehicle and measuring how quickly and forcefully its airbag deploys, whether or not it hits the driver’s head and whether or not its deployment requires extra force to deploy properly. This information helps manufacturers decide whether or not to deploy their airbag and how much force will be necessary.
At the scene of an accident, airbags are activated by an ignitor within, which triggers a chemical reaction producing gas that inflates them quickly – usually within 55 milliseconds – using harmless ingredients like talcum powder/cornstarch and nitrogen as primary constituents; sometimes additional sodium hydroxide may also be present in variable amounts.
Side Curtain Airbags
Front airbags can be very helpful during an accident, but they do little to provide relief in side impact crashes. That is where side curtain airbags, sometimes known as tubular or pillar airbags, come into play – protecting both drivers and rear passengers in case of rollover accidents.
These typically found on SUV’s, minivans and crossover vehicles with 3-row seating will deploy along their side glass to prevent occupant ejection during a collision and also protect rear seat occupants should a vehicle roll over.
Side curtain airbags provide a barrier that helps mitigate risks of ejection and reduce head injuries, making them increasingly popular with truck manufacturers as well. While front airbags typically come from one or two major OEM suppliers, side airbags come from many different suppliers which helps keep costs for consumers low; each side airbag costs automakers approximately $50 each to supply to automakers.
In an accident, knee airbags deploy from the lower dashboard to push against occupant legs and distribute impact forces more evenly, helping reduce leg injuries while working in conjunction with frontal airbags and seat belt pretensioners for frontal collision protection.
Some manufacturers use knee airbags to help their vehicles pass federally mandated tests with unbelted dummies, although the IIHS study didn’t focus on such accidents. Crash tests conducted by IIHS demonstrated that knee airbags actually increased lower leg and right femur injuries while head injuries were decreased by using them.
The IIHS research also looked at police-reported data from 14 states, comparing injury risks for cars with and without knee airbags. They determined that knee airbags had no discernible effect on injury risk, potentially even increasing it during certain collisions, and weren’t as effective when worn with a seat belt.