[hombre_fatal]

There could be a number of reasons from average vehicle size to urban planning norms to pedestrian culture. Maybe we jaywalk more on more dangerous roads with larger vehicles with less visibility and our fat bodies have larger hit boxes.

[atlasunshrugged]

I think the majority of the increased deaths are probably from the higher grills and weight -- instead of tumbling over the hood of a sedan, you get hit center mass by a truck or SUV which is far more damaging. That said, great point on jaywalking more, compared to when I was living in Germany or Estonia, we jaywalk far more (and engage in riskier activities in roadways like with scooters and ATVs) than those places.