What can seatbelt use data tell us about mask use?

To some of us, the recent mask debate in the US seems beyond ludicrous. The discussion has been mainly driven by politics with President Trump and his supporters alluding to their American freedoms as their defense for not being required to wear a mask. Those on the other side are quick to remind that you can’t drive a car without a license or insurance or they may quote the classic statement that you can’t “shout fire in a crowded theater.” While these are all true, I can’t remember a time when it was commonplace to see people doing any of these things.

What was commonplace and totally legal when I was a kid was not wearing a seatbelt. Drivers rarely used one and passengers never did, especially those in the back seat. I remember lying in the back of my family’s station wagon on long car trips so my siblings and I didn’t have to all be in the back seat. It was also common back then to put babies in the car in a simple basinet with no restraints at all.

Seatbelt Data & Laws
It’s not surprising that our state governments began to notice a correlation between auto fatalities and not wearing a seatbelt. And so, in the public interest, states began to pass laws. New York was the first state to establish a seatbelt law in 1984 and South Dakota was the last to do so in 1995. New Hampshire is the only state that never added a law for seatbelts. Now, all of these years later, we can look at the graph below and see that seatbelt use has steadily increased and the percentage of unrestrained auto deaths have shrunk.

So, the primary lesson here is clear. You may not always like it, but public policy can save lives, if only we listen to the experts. But what else can we see in these numbers?

Seatbelt Adoption Has Been Slow
First, looking just at the seatbelt usage rate, we see how long it has taken to move from 58% seat belt use to 91% seat belt use. Imagine how many lives could have been saved if people would have adopted this habit earlier. I was one of those people who had to get used to driving a different way — it felt uncomfortable and I admit it took me a little time. That said, 25 years seems a long enough and we’re still nowhere near 100%.

The Fatalities Are Worse Than They Appear
Another important lesson in the data can be found by looking at the numbers from a different perspective. Above, you may have noticed that. while seat belt use is way up, the number of people who die while not wearing a seat belt is still greater than 38%. If we look at the percentage of people who don’t wear a seat belt and divide that number into the fatality rate, we see something truly scary.

In 1994, 42% of people didn’t wear seatbelts and this group accounted for 57% of the fatalities. Today, only about 10% of people don’t wear seatbelts but they account for around 39% of deaths. This translates to a 200–300% increase in the chance that a person who died in an accident wasn’t wearing a seat belt. While the cause and effect for this trend probably involves several factors, I believe that the story boils down to something like this.

  • Cars have been made safer and safer but always under the assumption that people wear seat belts.
  • The few who don’t wear one are not benefiting from the technology as much as those who do.

Seatbelts vs. Masks
So, what does the last 25 years of seatbelt usage data teach us for our current situation?

  1. Public policy can be a very good thing and save lives. This suggests that we have a chance to improve our situation.
  2. Americans can be stubborn and it takes a long time to effect change, (especially when you add in political influencing). This suggests that we probably are fighting an uphill battle.
  3. Those who are the most stubborn become the most vulnerable. This suggests, unfortunately, that these people will bring many innocents down with them because, unlike a seatbelt, a mask is to protect others from you.

Data Sources: National Occupant Protection Use Survey (NOPUS) & Fatality Analysis Reporting System (FARS)

After spending my career in Marketing and Business Development, I am taking the Data Science Immersive course at GA and looking forward to the next step.