It's complicated. In the USA some states like South Carolina have higher rates of fatalities while others have fatalities per billion vehicle-km comparable to the best countries in Europe[1][2]:
USA and territories 7.1 (includes Guam, Samoa, Puerto Rico, etc.)
I think that if you compare by fatalities per km you should also take population density into account: 336 per km2 for Massachusetts vs. 501 per km2 in the Netherlands.
USA and territories 7.1 (includes Guam, Samoa, Puerto Rico, etc.)
USA, Massachusetts 3.25
Sweden 3.5
Netherlands 4.5
Belgium 7.3
Spain 7.8
Australia 5.2
Japan 8
S. Korea 16
Brazil 55.9
[1] https://en.wikipedia.org/wiki/List_of_countries_by_traffic-r...
[2] https://en.wikipedia.org/wiki/Transportation_safety_in_the_U...