THE MOSTLY FILLED cabs were still whooshing past people yesterday morning when we began our unscientific survey on the latest ruling to let the rider, not the driver, decide whether to pick up additional fares in mid-trip. Like this decision itself, it was a tossup, depending on each respondent's last battle report:

Respondent No. 1 not long ago hailed a cab at National Airport allegedly bound for Dupont Circle and wound up on a polar-route excursion via the Capitol. She's sick of being shanghaied and hails the decision. Respondent No. 2 waved in vain for an empty cab and was grateful for a partially peopled one that did stop and add her to the manifest for a trip downtown. She attacked the decision; she's happier when her fate is up to a driver, not a back-seat jury.

Cabdrivers on the whole are automatically not happy about much of anything, beginning with your looks and destination, and this new decision is right up there on their list. To hear it from them (and you will), a passenger-veto rule will rob them of perhaps 35 percent of their income, not to mention an undetermined percentage of their coveted and too-often- overasserted autonomy. Besides, they argue, wasn't this nice fare-share system meant to help save gasoline and do something about the energy crisis?

That's right, and just because the gas shortage is not with us today is no reason to resume wasteful habits. But the real issue here is not gasoline. It is the number of drivers who do too much picking and choosing of passengers already, and who bully visitors and other helpless passengers into absurd side trips (the legal limit now is a five-block deviation). True, this may be only a minority of the drivers out there. But until they find some better way to police themselves, the weight of authority should shift more to the passenger.

Besides, the majority of Washington's cabdrivers, who do their jobs with enthusiasm, courtesy, fairness and a respect for the rules, should find business about the same--with most passengers willing to consider a fair request to help out another rider. And maybe those drivers who ignore too many rules already will turn in their permits in protest. Good riddance.