IN A STARTLING reaffirmation of their self-centered, irresponsible behavior since taking office, three mischievous members of the D.C. Taxicab Commission have approved a fare surcharge that is sure to shortchange the city's drivers and the public as well. If they didn't know any better or hadn't heard the opposition of almost every group in town -- not to mention their own chairman, whom they vilify at every opportunity -- these three members might be excused on grounds of ineptitude. But panel members Joseph Becker, John Jessamy and Lucille Johnson have consistently rejected any thoughtful proposals -- including those endorsed by an accounting firm that the commission hired.

The surcharge -- 40 cents a ride -- is referred to as an interim measure (translation: the three in the majority can string out their $150-a-session meetings to keep on arguing with chairman Arrington Dixon and the fifth member, cabdriver Yale Lewis). The effect is small change for drivers and more trouble for passengers because it will provide a new disincentive for drivers to pick up riders for the longer trips. Every reasonable proposal to come before the commissioners has involved some formula for increases for each zone traveled.

Washington's cabbies have not had a fare increase of any kind for almost three years. What they have had is word that they face a possible insurance rate increase of more than $600 a year starting in June as well as huge increases in assessments and fees. Just when local authorities have made progress clearing this city's streets of many unlicensed and unscrupulous drivers, the message to the honest majority seems to be to make do on less or break the rules and go for the short rides.

If Chairman Dixon can't find a legal way to set aside this decision, Mayor Barry and anybody who cares on the D.C. Council should do whatever it takes to restructure, replace or overrule those who have no sense of their responsibility.