Per the article, it does work (or works better) when the desired (more optimal) behavior is communicated to the drivers. One of the major issues (as one of your sibling posts points out) is a low quality or absent driver education. It's not just enough to know to use the brake, signals, shifter, and throttle. Drivers need to understand how traffic flow works as well. Absent this awareness, they need to be taught rules/heuristics of behavior (like the signs attempt to communicate).