Which Would You Rather Have: A Seat Belt or an Air Bag?

A number of readers, in light of our recent column on car seats vs. seat belts for kids, have asked my views on seat belts and air bags for adults. So let me ask you a question: if you could only have one or the other, would you go for the seat belt or the air bag.

It turns out the answer is easy, and my views on this one are much less controversial than on car seats. With Jack Porter, a professor at
Wisconsin, I wrote a paper published four years ago that looks at the effectiveness of seat belts and air bags for adults. We found that wearing a seat belt reduced the chance of death by 60-70 percent across all crashes. We estimated that air bags reduce the death rate by 15 percent in frontal crashes, but don’t help in partial frontal, side, or rear crashes. (The benefits we found for adults in seat belts were higher than most previous research, and the results on air bags were lower than in most earlier research. But there is nobody who knows the data who would prefer an airbag to a seat belt if it was an either/or choice.)

The bottom line is that to save a life with a seat belt costs $30,000; to save a life with an air bag costs $1.8 mm by our estimates. This makes seat belts an incredibly effective safety innovation. While in comparison, air bags look bad, indeed in the scheme of things $1.8 mm to save a life is pretty good by regulatory standards.

Along the way in doing this research, we also were able to dispatch with an urban legend. I have heard people say a number of times how drunks manage to survive crashes better than sober people, which has led ER docs to hypothesize that having alcohol in your system relaxes you and allows you to better absorb the blow of the crash. It may surprise you that drunks really are more likely to survive crashes. But the reason isn’t that they are “loose,” it is that the person who makes a mistake in a crash often rams the front of their car into the side of the innocent person’s vehicle. And for survival purposes you would much rather be the one ramming another vehicle than the one getting broadsided.

Speaking of urban legends, anyone know where we can find OrangeJello, LemonJello, and Shithead? Seriously, we want to talk to them.

Scott Cunningham

My mother-in-law apparently was colleagues with their teacher. Ironically, I was just asking her about it this morning (as I thought it was her, but turns out, it was just someone she was in graduate school with). If I can dig it up, I'll email it.

The Eclectic Econoclast

I expect that one thing left out of the statistics is that airbags reduce the number of suicide attempts from running into trees and bridge abutments, especially suicides by people who want their deaths to appear to accidents, for insurance purposes. If your car has an airbag, you can't very easily kill yourself this way. But I have no idea about the size of this effect.

Of course you can still do so by pulling out in front of a train or truck (if your car doesn't have side airbags or curtains), but many people contemplating suicide don't really want to inflict that on the driver of another vehicle.

Abbot Uhhm

When I was growing up the stories about the drunks surviving crashes usually involved out-of-control, went off the road, hit a tree accidents. Having survived one of those myself (stone-cold sober) I'd say we tend to attribute a reason to things that sometimes either don't make any sense, or are just the results of the finger of God.



Do you also attribute the high casualty rate among people who get blind-sided to the finger of God? Perhaps the middle finger?

I've got no problem chalking up random lives saved and ended up to acts of God. But don't you think it's a bit silly to ignore a common sense explanation (that is, having an engine absorbing much of the crash rather than just the side door) combined with the data showing the hypothesis is true?

I think we have a tendency to attribute God as a reason to things we don't understand, rather than just admitting that we don't know.

Abbot Uhhm

Well no. I think there's a reasonable assumption that the blindsided are more likely to be injured than the blindsider. I actually saw this illustrated when a Saturn wagon blindsided and knocked over an SUV, disproving the lie that SUV's greater height makes them safer vehicles. My comments were about drunks involved in single car off-the-road accidents.

You are correct that I do not know why I survived the rollover down the canyon.


Your blog is not clear as to what benefit airbags are to individuals wearing seatbelts. Or is that the cost/benefit ratio you cited fir airbags?


Air bags may be worse than most folks think. maybe UNsafe.

Our 2005 Honda CR-V was hit broadside by a Ford F250 truck as the truck pulled out of a gas station.
(Driver probably drunk - it was a hit & run)
Speed estimate for the truck: 30MPH to maybe 40.
We were doing about 20-25 due to traffic light.

Side curtain airbags went off on my side (front passenger).

6 weeks later may ears are still ringing loudly. The ENT doc tells me there is no treatment.
My fade with time - maybe not.

Mike Linksvayer

What do you think of claims that airbags are associated with an increased chance of death in accidents?


Jim Voigt

How does your data play out considering that cars now have both airbags and seatbelts. You never said "don't use an airbag" and obviously didn't advocate disconnecting them or anything. Basically, how do we apply this data with regard to modern cars? If the airbag is an option you have pay for on a new car, is it worth it? We skipped an optional passenger airbag several years ago on my wife's car. Bad call?

Anon noted hearing damage from the airbag. My sister-in-law had her life saved by an airbag, but it did cause hearing damage for about a year. It clearly saved her life, so she didn't care. But is there a way to collect data to determine how often an airbag goes off, causes hearing damage, but doesn't really affect the survivability of a crash or degree of injury in a crash? In other words, how often does an airbag cause more damage than it prevents, and is this balanced out by the frequency with which airbags save lives that otherwise would have been lost?

Any plans on looking at ABS?



OrangeJello and LemonJello are supposedly deputy sheriffs in Clarke County, Georgia. The phone number for the sheriff's office is 706-613-3250. (ACC Phone Listings)

-Peter Collopy


Anonymous, your post doesn't make clear whether the airbag that damaged your hearing also protected your safety. From the speeds of the vehicles involved it sounds like it would have.


A girl with the first name "Pepsi Cola" attended high school or college (I don't remember which) with my mother in the late 1940's-early 1950's.


noumenon - Tough question to answer without a replay but ...
My guess is the bags did not save me from any damage. The passenger window was 95% down. It did shatter but the glass shards were almost completely within the door.

If the collision had been head-on the speeds of the two vehicles would have been added.
This collision was from the side and the impact zone was both the front and rear doors.
The side was not pushed in enough to impact/damage the seat materials.

Also -
The police at the scene said that ringing in the ears was common with airbags and it would go away over time. Not yet true for me at 6+ weeks.


Of course, seatbelts also have the advantage of almost never killing someone they're trying to protect. Airbag-induced fatalities are still happening, and are likely under represented in the offical statistics.

66 Rustang

I heard the "lap style" of seat belts have contributed to fatalities because it only has one point of retstraint which would cause internal bleeding.


The "either/or" air bag vs. seat belt dichotomy is misleading. Airbags have always been considered supplemental safety restraints, not primary safety restraints like seatbelts. In other words, air bags are intended to be used in conjunction with seat belts, not without. Air bag fatalities are very rare, and are primarily caused by parents putting young children in the front passenger seat.

I do know that OrangeJello and LemonJello lived in Los Angeles County as kids. Where are they now? Who knows?

David Yaffe

Hey Steven

What is $1.8 "mm", sorry if I sound naive. I hate to make a "plug" but check out my new blog. Apparently Bush's U.S. Supreme Court Justice nominee tried to overturn Roe v. Wade. Should we have him read your book?


As a short person (5ft 1) I am always uncomfortable with the use of airbags - but I don't have a choice about using them - here in Canada I would have had a major legal headache to go through to have the airbag in our car turned off which really pisses me off (especially when I was pregnant). I don't think airbags should be mandatory - and I do think we should have a choice whether or not we want to use the ones installed in our cars.

Brian C Merrell

As a tall person (6'3") I am concerned about breaking my neck on the ceiling of my (small Japanese) car even if the airbag were to deploy. I've hit my head on it leaning forward to see stoplights before, so I really worry what would happen if I slammed into something in a frontal collision (supposedly the 'safest' sort of crash).


Here's the real question: how many accidents are prevented by seat belts?

Your body's inertal weight is equal to WEIGHT X SPEED. The other day I had to stop suddenly and the seatbelt held me on the seat. The seatbelt also helps hold you to the seat when maneuvering. If you are not in control of your body then it is more difficult to be in complete control of the car.

The flip side of the seatbelt/airbag safety argument is what I like to call Dave's Rule of Natural Selection. Definition: Observation of stupid behavior that makes me think that if they are strong enough to survive said stupid behavior then they deserve to live(ie: carrying infant in lap next to airbag while driving).