I can see those kinds of things working in or near cities, but out where I am - fairly rural - there's just too many miles of road to install a bunch of speed humps or similar things. It would take a monumental amount of money. They don't even have shoulders on most of the roads. I admit even I speed when I'm driving them, although I'll slow down for bends in the road so as not to clobber a deer, cyclist, pedestrian, etc. that might be lurking out of sight.

(I got into a fun argument here on Lemmy a few months back with someone who insisted horse and buggies should have lights, and I was like, "What happens when you come around the bend too fast and there's a tree laying in the road?" He just couldn't accept the problem is the driver, not the horse and buggy. Basically, that's what's wrong with drivers in the US: We, as a group, have a bizarre expectation that things will always go to plan.)

I'm also nervous about these solutions for another reason - I've seen towns install those kinds of calming measures in a way that hurts cyclists. In one example, they extended the curbs out to the lane, which does slow down traffic - but it forces cyclists who could previously ride on the shoulder into the lane, thereby further enraging drivers. I had one asshole pass me in that very narrow section some years ago, so now I make sure to ride in the middle of it, so they'd actually have to hit me. They won't do that because they don't want to damage their precious car, so I'm safe.

And I say this as someone that lives in an area that's actually pretty good for cycling, that is, most drivers are actually pretty good about passing safely and all that.