I have driven in both the US and a few European countries, and I would disagree with your proposed cause but agree somewhat with the effect. Having driven on long-distance road trips in the US, drivers are noticeably more competent than in (sub)urban highways, probably because the latter are filled with drivers who don't drive as much at those speeds. This is often inherently true in many western European countries in which driving usually has reasonable public transit alternatives so the selection of drivers on roads may tend to be more skilled and experienced.

That being said, in some European cities drivers are not very keen to stop for pedestrians in crosswalks, even when pedestrians are already in the median "island." I haven't noticed any US city of a similar size that had drivers quite so negligent about crosswalks.