THE DECISION BY the governors of Maryland and Virginia and the mayor of the District to drop the odd-even gasoline rule as of Oct. 1 is a bad idea. However much of a nuisance the restriction now seems, it is a constant reminder that gasoline conservation is still important, that "the problem" of supply has not disappeared. What has disappeared for now -- thanks in no small way to the odd-even, minimum-purchase ground rules for distribution -- is panic at the pumps.

Declaring open season on gas supplies invites a return to "normal" -- excessive is the word -- use. This could produce another severe shortage at area pumps; and if that leads to another decision to bring back the odd-even rule, it couldn't help reinforcing public suspicions that the whole thing is a sham in the first place. Besides, there is reason even now to believe that soon there will be new pressures on filling-station supplies. In the past, September has been a month of weaker demand; but use in October tends to match that of May and June -- which was when this year's pandemonium at the filling stations erupted.

True, the odd-even rule has its flaws. Such a rule made uniform across the country would be more effective than regional restrictions, for instance. And it is also true that the area rules have not been observed or enforced all that strictly. But this is not a good reason to lift them. The effect of ending the restrictions in this region will be to convey the notion that the situation has improved enough for people to disregard the problem. There is still time for the two governors and the mayor to reconsider their decision. They should.