The greatest number of accidents I’ve seen have been at stop lights rather than stop signs, weirdly. Driver apprehension and cautiousness at four-way stops may actually prevent more incidents than other systems.
I think the idea is that you should yield and only go when it is clear. But because of the length of the ramp, I think they are legally required to have a merge sign there. Invariably people fail to yield, and, since it is uphill, 'merge' into 45 mph traffic at 20 mph. And by merge I mean they just drive on and expect people to stay out of their way.
I have way more problems with people turning on red at the worst possible moment (despite lots of previous safe opportunities) than I do with yield signs though. But I don't doubt the GP's experience either. Drivers are very different in different states and regions of the U.S.
And traffic circles? Fuck that's super confusing! Americans would rather get into accidents at a four way stop than be confused in a traffic circle. That's why traffic circles are so uncommon.