Perhaps you're right regarding what the comparison is inviting. It might not be suggesting cross-country comparisons, but it's still making a normative statement concerning the ideal. My contention is that it should not do that; it should only focus on the decreased probability of death by reducing speed. Weighting the trade-offs is too objective.
A Canadian paper on US data, not enough people actually live in Canada for cars to approach each other on average. (I'm Canadian, but also making fun of the abuse of averages to describe this data).
No, it very clearly is only suggesting that Americans are doing something inferior compared to the ideal.