so what do those stats say vs Germany, Sweden, the EU average? all very easily searchable, no mechanistic theorycrafting required. how does the US fare? certainly not multiple times worse across the board, right?
Would it? How much of the statistics are attributable to a difference in standards vs the higher average speed and larger average vehicles in the US? Physics is a harsh mistress, both of those factors have a lot of effect on crash energy.
you're also claiming a multiplier for fatality rates for car sizes. and there is a significant difference (https://hannahritchie.substack.com/p/global-car-economy) but the fun fact is that all cars around the world are getting much heavier - the US isn't even the leader in terms of how much cars have ballooned, only in that the starting point was higher
but for changes like that, you can control for fatality rates across time, correct? what do those numbers say? have bigger cars led to increased fatality rates? the IIHS has that data. what's that trendline look like? and what about Europe? there's data for that here: https://road-safety.transport.ec.europa.eu/system/files/2022... - page 10 seems to indicate a trend