Did a bit of research: https://news.ycombinator.com/item?id=47121031 - different countries have different legal requirements, despite air being the same everywhere.
One of them must be better aerodynamically though, must'n it?
Furthermore Europe has relatively strict speed limits on trucks, which makes aero something of a lesser factor since drag grows to the square of speed: european trucks at european speeds have a pretty significantly higher efficiency than US trucks at US speeds.
And that assumes the speed limits are respected at all, but the EU has required a hard 90kph limiter since 2005, tampering with the limiter is a criminal offense, so is tampering with the (also mandatory) tachograph which would reveal the first.
So while nothing prevents speeding up to that (and it very much happens) going higher becomes extremely dicey.
I fear even that is misleading. Yes, the speed limits on undivided highways are often 55 in the north-east (or even 50 in a couple), but the speed limits on divided highways are all higher, ranging from 65-75 mph. See the two maps on the top right: https://en.wikipedia.org/wiki/Speed_limits_in_the_United_Sta.... I suspect that the majority of truck miles are on divided highways.
I've seen truck speed limits of 55 pretty much everywhere I've been except Texas, though.
But that goes directly against TFA, doesn't it? The final image is closer to the European design than the American one? Or am I misunderstanding the article?
> they are potenitilly safer
Maybe for the occupants, but for everyone else they seem strictly worse, not to mention the visibility much be much much worse, making it a somwhat iffy tradeoff.
The air may be the same everywhere, but roads and safety laws aren't.