I think a lot of it is regional. In big city-center-compacted cities it works well, NYC being a great example. In suburbs it's sort of sloppy or depends on the area. In sprawling everyone-in-SUV-8-lane-highway cities, places like LA or Houston, it's an absolutely hopeless shit show of selfishness.
I have theories on why it's that way, but all I really know is that's what I have observed.