Seems to me that we get into the most trouble when we go looking for "one big answer." There might be local circumstances that make a certain type of divider the best or even the only practical solution. Local discussion here just mentioned cable dividers as a possibility for the Patullo Bridge, notorious for head-ons, where there is no room for any other kind of divider without widening the whole bridge.
Knowing what I know now, however (and thanks, Big Thumb; that article was a real education!), if I were riding a motorcycle I would be putt-putting along in the right-hand lane wherever a cable barrier exists. That way no ignoramus driver in a car with a designed-in blind spot and no interest in side mirrors can punt you into the barrier, and you don't careen into it by your own overestimation of your abilities to handle the bike.