This study from The Economist finds that for every 1 life the heaviest 1% of passenger vehicles save, they take 12 lives in other cars. NZ needs to avoid the US' vehicle arms race. Tax vehicles by weight and require heavy vehicle licences for big double-cab utes.
https://www.economist.com/interactive/united-states/2024/08/31/americans-love-affair-with-big-cars-is-killing-them