fwiw and not to diminish your point, semi trucks in Canada are rarely heard, they mostly drive along our massive highways, they are generally not allowed in cities, and you can drive from one end of Canada to the other (east <> west) on Highway 1 without entering cities/big towns, the most populated area you have to drive through is at the Ontario/Manitoba border. (Source, I've driven Canada fully, end to end e->w)
I mean, they’re rarely heard by people, but they’re certainly heard by everything else trying to live near the highway that as you said, cuts across the entire country.
Now, not to say you don’t make a good point, but noise pollution is pollution, and reducing it does have benefits.
I severely underestimated how loud a single semi was until I was camping 5km from a highway and couldn’t hear the cars, but could certainly hear the trucks.
