The psychology of this seems easy to explain, too. Stop signs get folks into a routine of basically, "stop, see nothing is there to stop for, start moving." Do that enough times, and you accidentally move on to "start moving" from habit alone. Contrast that with things that have you slow down, where you will slow down every time from the same learned habit. Even if you accidentally move on and potentially hit something, you will have at least slowed considerably beforehand.

(Yes, you should also be coming to a full stop, but it is impressive how rapidly people will go through the motions of "stop, look, go" to the point that they don't realize they didn't finish any one step. Similar to talking, all told. In speech, most words blend together and you don't have meaningful stops between all words.)