MANY FARECARD FIASCOES AGO, Metro board member Francis B. Francois of Prince George's County suggested rather strongly to his colleagues that the subway system's multimillion-dollar fare-collection equipment had been a flop. He was right, but even those who might have agreed with him preferred to pray that things would improve. Things didn't. And now, for reasons we all know too well, there has been a surge in subway ridership; more people than anyone predicted are riding the rails - and the Farecard system is clearly not up to the job. So why doesn't Metro simply get rid of the system and start over?

It should, but it won't - until some monumental political problems are overcome. This is not to say that improvements are out of the question; Metro General Manager Richard S. Page is properly demanding that the manufacturer get on this case with a sense of emergency. And parts of the Farecard system may be abandoned: For example, new rail-only passes could be devised, which employers might even subsidized instead of parking privileges, or monthly passes could be used, so riders could avoid exit gates.

But the fundamental problem is not the Farecard itself, as much as it is the fares, and therein lie the political complexities.There should be a flat subway fare, or at most two fares, for the entire system. Then you wouldn't need Farecards at all. But the reason for Metro's esoteric fare schedule (certifiably the most complicated in the country) is political: Scratch all the polite generalities of regionalism and you find sharp and usually bitter philosophical differences between the participating local governments over what Metro should be trying to do for the 3 million people of Greater Washington - and how to do it. If, for example, the District government continues to insist on freezing D.C. fares while the suburban governments press for higher fares to relieve growing subsidies, you are not on your way to a flat fare. If the governments do not agree on how other factors should be weighed - numbers of riders in each jurisdiction, miles traveled, cost of construction or any other imperfect methods - you won't see it, either. Without some uniform regional tax plan to raise revenue for Metro, still other hurdles remain.

So in the short run, Mr. Page, Mr. Francois and other leaders of Metro at least are trying to work out some ways to make the Farecard system work better. But to meet the growing demands on Metro in the years to come, they and other politicians in the District, Maryland and Virginia should consider something far more revolutionary, something most of them will dismiss as politically impossible: new agreements and revisions of the original Metro compact between the two states, the District and the federal government to pave the way for a uniform regional tax and a simple fare structure.