@katie@mstdn.io

I didn't even look this up when I fired off that toot. It just seemed that the increase is likely due to a comparatively low number in 2020 due to covid, rather than something special in '21.

I just now looked up the press release and sure enough it says, "...vehicle miles traveled in the first half of 2021 increased by about 173.1 billion miles, or about 13%. "

So that's likely why fatalities increased. The accident and fatality rate will go up, but it is not going to go up linearly with the increase in miles traveled because when there are more cars on the road they are more likely to bump into each other. So it makes sense that a ~13% increase in vehicles on the road results in a ~18+ increase in accidents/fatalities.