WITH A TEAM of generous arbitrators at the wheel, Metro's 5,000 workers have just taken the whole transit system -- and all its paying customers -- for the biggest ride ever. Under an ever-so-binding decision issued this week, the transit workers have successfully defended their title as local-government employees best protected against inflation. And if that makes the rest of the employees green with envy, they and every other taxpayer in the region will need wallets to match -- because this deal is going to cost a bundle.

Local governments and taxpayers, who already pour in more than $110 million in subsidies to Metro, not to mention higher and higher fares, do have an unattractive alternative: they can cut bus and/or subway service -- and let those jobs fall where they may. This, like it or not, is the reckless route on which the union is taking its members; the new contract, which is the most expensive one in recent big-city memory, could well drive many employees right off the roster. No wonder Metro General Manager Richard S. Page is shocked. No other public employees around here -- teachers, firefighters or police officers -- have such a deal as the arbitrators have cut for the transit workers.

While area governments are trying to hold employees in their jurisdictions to increases in the neighborhood of 5 percent, Metro's workers will be receiving quarterly -- repeat, quarterly -- salary increases that match the first 9 percentage points of increase in the national Consumer Price Index; for each point over 9, Metro will have to pay two-thirds of 1 percent.

Mr. Page says he is considering recommending that the binding arbitration requirement be stricken from the Metro compact. He should move on it, even though this will take some doing; identical changes would have to be made by Congress, the Maryland and Virginia legislatures and the District Council. But now's the time, since all of these government players will be on duty for business next month. For the good of their constituents, including other union members struggling to stay even with inflation, all responsible members of these government bodies should see to it that the process leading up to this outlandish settlement is changed drastically -- and quickly.