I live near a fairly busy (~3,000 vehicles/day) intersection that is controlled with a yield sign, which is itself a very unusual feature for this area.

This enables me to spend as much time as I wish observing how people use it.

Some people get it right. Many get it wrong -- either treating it like a stop sign (it isn't), or treating it as a Just Go sign (it isn't).

However, what's perhaps actually-interesting is that I've not noticed any wrecks there -- ever. So however it does or does not work, it seems to at least be "safe."

Except for the "you really ought to merge here" type yields where of course they must stop.