Question: Do airbags work better than seat belts for protecting you in a crash? And if they do, shouldn’t the law be that you only have to wear seat belts if your car doesn’t have airbags?
Answer: Seat belts are arguably the most effective thing that has ever happened to traffic safety. I won’t quote all the studies, but depending on which one you look at, seat belts reduce fatalities in crashes by 50 percent to 70 percent. That’s a huge increase in survivability for a minimal effort by a driver (the couple seconds it takes to buckle up) and a modest cost to the manufacturer (the price of the seat belts).
Here’s another way to look at it. In Washington we have a 94 percent seat belt-use rate. Only about six out of every 100 people on the road are not wearing a seat belt. However, about 20 percent of the people killed in car crashes in our state are not wearing a seat belt. That 6 percent non-seat belt-user group is severely over-represented in fatal crashes.
I think I’ve established that seat belts are effective, but what about airbags? When it comes to surviving a crash, airbags alone are not nearly as helpful as seat belts. Airbags only reduce fatalities in car crashes about 15 percent when the driver isn’t wearing a seat belt. That makes sense; in order for an airbag to be helpful, it needs to be deployed where you’re at. If you’re in your seat, it’ll help protect you. Without a seat belt, you could be thrown around to a lot of places, both inside and outside your car, while the airbag is still just doing its thing protecting whoever is in the seat.
When a driver wears a seat belt and has an airbag, the airbag doesn’t add 15 percent to the 50-plus percent reduction in fatality rates that a seat belt offers. Combined it’s only a couple percent better than seat belts alone.
Clearly, airbags are not a great substitute for seat belts, and a law that requires drivers to wear a seat belt only if the car doesn’t have airbags would be a move away from safer roads. Maybe the better question is, “If airbags have such a minimal impact on the survivability of a crash compared to seat belts, why are they such a big deal?”
So far we’ve been talking about fatal crashes, but just because a seat belt saves your life it doesn’t mean you won’t be seriously injured. That’s where airbags really shine. An article in the International Journal of Critical Illness and Injury Science compared the injuries of two occupants of a vehicle in a serious crash. Both were wearing seat belts but only one had the benefit of an airbag. I wouldn’t recommend reading the article during lunch, or if you have a sensitive stomach, because the injury photos are graphic. Instead I’ll summarize: With only a seat belt, the pattern of injury corresponds to concentrated areas where the seat belt is against the body. This results in more severe intestine, kidney and spinal injuries. An airbag spreads out the impact and reduces the trauma to the body.
Airbags are a supplement to seat belts. You may have seen the letters “SRS” on the dash and steering wheel of some cars. That’s an abbreviation for “Supplemental Restraint System.” Airbags were never intended to replace seat belts, but are very effective at reducing injury when used with seat belts. Still, wearing a seat belt is your best strategy for surviving a car crash.
I’ll just add that even better than surviving a car crash is not getting into one in the first place. Being an alert and educated driver can help you avoid becoming part Washington’s crash data.
On a final note, we’re in the middle of seat belt emphasis patrols, and local law enforcement agencies are out looking for drivers who are not wearing a seat belt. If you’re part of that 6 percent that still doesn’t buckle up, this would be a good time to join the 94 percent and develop a new habit.
Road Rules is a regular column on road laws, safe driving habits and general police practices. Doug Dahl is the Target Zero Manager for the Whatcom County Traffic Safety Task Force. Target Zero is Washington’s vision to reduce traffic fatalities and serious injuries to zero by 2030. For more traffic safety information visit TheWiseDrive.com. Ask a question.