My colleague who has a boyfriend in New York has become something of an expert on taking cabs to and from National Airport. She knows that the fare should be $6.70, but that is hardly ever the amount she is charged. Instead, drivers look at their fare charts, compute the mileage and then apparently make up the amount. The only thing more chancy than riding a cab in Washington (aside maybe from voting) is taking the Metro.

The reason for this is that both the taxi system and the Metro system subscribe to the governing philosophy of public transporation in the Washington area, which is that it should serve the ones who run it, not the ones who use it -- the public.

This is certainly the case with cabs. It goes without saying that one way to improve matters is to put meters in cabs. With meters, both the driver and the passenger know what the fare is and you don't have to spend the entire ride wondering if at the end you are going to get into a brawl with a driver armed with a fare schedule and zone map that looks like Marion Barry's astrological chart, with Zone One ascending.

This is the case also with Metro. The prime reason for the wonderful Farecard system is the insistence of the local governments that passengers who ride the longest distance be charged accordingly. Under this system, it is considered a catastrophe if everyone pays the same and if all the local governments bear the costs equally. The upshot is a fare system that is, in its own way, as vexing and as stomach-knotting as the one used by the taxi industry -- in other words: chaos.

In this case, chaos by another name is called a Farecard. It can only be bought from a machine that often is out of order or will not make change or can only be reached by a long line of people who, despite full and varied educations, cannot figure out how to make it work.

Compounding the situation is the fact that Washington -- I know this comes as a surprise to Metro -- is a tourist town. At certain times of the year, it is inundated with people who do not have the foggiest notion of how to use a Farecard machine. You do not know the meaning of confusion and panic until you have lined up in back of a group of foreign tourists trying to figure out how to get a newspaper out of the Farecard machine or a Farecard out of the newspaper machine. I exaggerate, but not by much.

At the destination lies more trouble. There you have to mess with computerized turnstiles clearly designed by the same people who have figured out how to foul up escalators. On a given day, some or many of these turnstiles are out of order, some are for entry only and the remainder are clogged by people who have fed the thing an indigestible Farecard, possibly under the naive assumption that the amount printed on the card corresponds to the value of the card. Under these circumstances, it is little wonder that Metro is no longer the darling of the Washington area and that its ridership is lower than projected.

The thing is a computerized mess. Trains don't run on time, break down far too often and have even been derailed for reasons no one can figure out. If Alexander Haig were running the system, he would blame the malfunctions on "sinister forces," but the actual explanation is more mundane. Metro remains a compromise between the demands of politics and the demands of public transporation. Everyone wants the latter, but no one much wants to pay for it -- especially for riders who are not political constituents. Fairfax understandably does not want to pay for a Washington ridership. The concept of regionalism ends at the pocketbook.

The upshot is a public transportation version of the hospital that wakes up patients to give them sleeping pills, restaurants who have "no substitution" policies written on their menus and banks that in the name of serving the customer better have installed automatic teller machines, thus moving the lines into the rain.

All these institutions have their loyalties in the wrong place, but they are pikers compared to Metro and the cab system, both of which have compromised their functions. I, for one, would demand action, but knowing this town, I am afraid of what might happen.

We would get Farecards in the cabs and a zone system for the subway.