Only airbags would tell you it’s safe not to wear seatbelt

Q: I have a car with 10 air bags. If I get in a crash I’m going to be floating in a balloon-filled cabin. With that many airbags, is the seatbelt still necessary? I realize it’s the law, but from a safety perspective how much does it help anymore?

A: Not only are airbags an effective safety feature, they also function as a prompt for jokes. Like these: New cars come with up to a dozen airbags, and that doesn’t count your passengers. New cars have so many airbags that they’re beginning to rival a political convention. Airbags – inspired by a road trip with your in-laws. I didn’t say they’d be good jokes.

You might think that with all those balloons inflating almost instantly in a crash, a seatbelt isn’t as important as it once was. And if you did think that, you’d be mistaken.

If you look closely at your steering wheel and the other airbag locations in your car, you’ll probably find the letters “SRS”. That stands for “Supplemental Restraint System.” Airbags are designed to supplement seatbelts, so there’s a design assumption that people in the car are wearing seatbelts. That’s a reasonable expectation; in Washington, for example, 93% of us wear a seatbelt.

Seatbelt effectiveness is undebatable. Wearing your seatbelt drops your risk of dying in a crash by 45%.

By some estimates, seatbelts combined with airbags push that to over 60%. Airbags alone, though, are not so impressive. According to the National Highway Traffic Safety Administration, in 2017 seatbelts saved 14,955 lives, while airbags saved 2,790 lives. And on their own, airbags can inflict harm. When you wear a seatbelt in a crash, your airbag helps to further decrease your odds of injury. That nearly instant inflation isn’t so great though if you’re not wearing a seatbelt.

Consider what happens in a head-on crash. Newton’s First Law of Motion states that an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force. When a car stops upon impact, the driver of that car continues in the same direction and speed until they’re stopped, by the seatbelt and airbags when used and so equipped, or by the steering wheel and windshield when not used.

The seatbelt restrains your torso, but at the top of your torso is a 10-pound ball with some stuff in it that you depend on for survival. That ball keeps moving forward until stopped by your neck. The airbag fills in that space, supporting your head and spreading out the overall impact to your body.

Without the seatbelt though, in a crash you’ll be rapidly moving toward a balloon that’s exploding at up to 200 mph. When it’s fully deployed it’s a cushion, but at first, it’s a rocket. Get too close and you have the potential for serious injuries from the airbag. The seatbelt keeps you in position to get the safety benefits of the airbag and avoid the initial giant punch from it.

For all the lives saved by airbags, there have been some deaths (partly because early airbag designs were too powerful), but in over 80% of those deaths, the people were not wearing a seatbelt or improperly restrained. Airbags work, but only when paired with your seatbelt.

Doug Dahl writes a weekly column for this newspaper. He is with the state Traffic Safety Commission.