Seat belt use: Discussion of observational research (with mask-wearing bonus discussion)

[sue_frantz]

It’s not very often we get to watch the birth of a social norm. Or at least not on this scale, nor at this speed. Mask-wearing was practically non-existent in the U.S. in March 2020. In late July, while certainly not universal, mask-wearing has become more common. As I’ve watched the norm shift in my community over these last few months, I’ve wondered about how other norms came into being.

For example, seat belt use. In 1968, the U.S. law went into effect requiring all vehicles to have seat belts—except buses, such as the ones that carry children to and from school. It wasn’t until the mid-1980s that many states enacted seatbelt laws—wear a seatbelt or get fined. Now 90% of people in the U.S. wear seatbelts, with just about every state showing increased percentages since 2004, according to the National Highway Traffic Safety Administration (data for 2004 to 2011; data for 2012-2019).

In looking at the data, my first thought was, how did they get these data? Self-report surveys? Nope. The data come from observational studies conducted by each state using a uniform set of observational criteria, called “Uniform Criteria for State Observational Surveys of Seat Belt Use.” I kid you not.

After covering observational research, present this scenario to your students (in a synchronous or asynchronous discussion):

Congratulations! You received a federal grant to conduct research on seat belt use in our state/territory. Your task is to estimate seat belt use.

1. How would you select where you are going to do your observations? Are there particular places you would exclude? Explain your rationale.
2. What time of day would you do your observations? Are there particular times you would exclude? Explain your rationale.
3. Who would you observe? Just the driver or also passengers? Explain your rationale.
4. If you’re observing at an intersection, would you observe all cars at the intersection? Or just those traveling, say, north/south or east/west? How would you decide? Explain your rationale.
5. If you’re observing a two-lane road, would you observe cars traveling in both directions, or just one direction? How would you decide? Explain your rationale.
6. Because of the scope of this study, you will need to hire and train people to do the observations. How would you ensure that the observations they make are accurate? Explain your rationale.

After students have made their responses to these questions:

Visit the Uniform Criteria for State Observational Surveys of Seat Belt Use. These are the criteria the National Highway Traffic Safety Administration (NHTSA) gives to states to conduct their annual seat belt studies. The reports are then compiled and sent to the NHTSA. You can see the compiled data for 2012-2019.

For A through F, compare your criteria with those of the NHTSA, particularly sections 1340.5 through 1340.8. Would you be in compliance? If not, what would you need to change?

In reflecting on everyone’s initial observations plans, who came closest to the NHTSA criteria? Explain your choice.

If you’d like to expand this discussion, consider asking students to take what they learned from the NHTSA criteria and use it to answer these questions about the prevalence of mask-wearing in your state/territory.

1. How would you select where you are going to do your observations? Are there particular places you would exclude? Explain your rationale.
2. What time of day would you do your observations? Are there particular times you would exclude? Explain your rationale.
3. Who would you observe? Adults only or children, too? Explain your rationale.
4. Where would you do your observations? How would you decide? Explain your rationale.
5. Because of the scope of this study, you will need to hire and train people to do the observations. How would you ensure that the observations they make are accurate? Explain your rationale.
6. How would define “mask-wearing”? Would any facial covering count? Does it need to be covering the nose? Explain your rationale.