Base rate matters though; for example if literally everyone is speeding because speed limits are too low then every accident will involve someone speeding.
is that really the case though, or is it people are so self involved that they feel they are too important to have to move that slowly? Just because everyone else is speeding does not automatically mean that faster speed is safe. It could also just be that people are assholes and they do what they want.
The tongue-in-cheek way it was explained to me once was "the highway isn't 70 because you need that. It's 70 because the trucker driving sleep-deprived in a light rain who doesn't know his left tire is about to blow needs that."
Then it still isn't good. The downsides outweigh the upsides.
A few decades ago the NYS Thruway caused a bit of political controversy because they started issuing speeding tickets if you traveled between two tollbooths faster than would be possible going the speed limit.
i.e. "We used to believe lies about how people drive, but thanks to the presence of more concrete evidence we are disproving those false assumptions."
One of the things Alphabet discovered early on in the Waymo experiment that was an eye-opener to the whole industry is that auto accidents were probably underestimate by a factor of three. When they started rolling out vehicles on the road, the best numbers available for accidents-per-mile were insurance reports and NHTSA incident records. Having vehicles with cameras on the road continuously revealed that there were 300% more accidents than those numbers suggested because humans are bumping into each other due to mis-estimates at stoplights all the time, but nobody wants their insurance rates to go up so they just don't report those incidents.
What if ubiquitous mass surveillance is good actually because it forces us to come to grips with realities we'd rather pretend are otherwise?