Gas rationing with odd-even license plate numbers is not really rationing.
I think it is labeled rationing but is really an interesting form of externally imposed impulse control. Normally, with a ration, there is a prescribed amount available per person per period. Here, none of those constraints actually imply.
Instead, by imposing "rationing" what we are really doing is limiting impulse and fear. Impulse (at least half of consumers will now need to defer purchases by a day and all will need to plan somewhat) and fear (because there is now a plan, the desire to "get gas before they run out" eases as there is less concern about "running out"). I wonder who thought of it.