My favourite part was their reason for investigating this correlation in the first place:
The proximate causes of most crashes are human behaviors including speeding, inattention, tailgating, impairment, improper passing, disobeying a signal, failing to yield right-of-way, or other infractions. These behaviors might partially reflect health consciousness, safety mindedness, community spirit, or other psychological characteristics that are difficult to measure in a systematic manner.
“Instead, we theorized that individual adults who tend to resist public health recommendations might also neglect basic road safety guidelines.”
This is the most enjoyable study I have ever read.
Holy heck, the 72% increase in traffic crashes (48% after adjustment), 95% confidence interval, and actually comprehensive data they had access to in this actually makes these extremely strong and significant findings.
Getting in car crashes to own the libs