NOTHING ON THOSE new Metro maps shows any line running between Annapolis and Richmond -- but there just happens to be a strong transit connection between both state legislatures this month. The cost of buses -- or bus drivers, to be more specific -- is driving many local jurisdictions to take hard looks at their participation in the Metro network. Unless the Maryland and Virginia legislatures act now to trim the gravy train that's written into the Metro compact for employees' salaries, local secessions -- and whatever extra costs they might entail -- are likely to occur.

It's not that getting out of Metro means getting out of the red. On the contrary, as a detailed report by staff writer Douglas B Feaver noted the other day, to do without Metro would be to do without federal aid for buying buses, building garages or paying drivers; and it might still mean doing business with unions, even if it weren't the same ones. But unless the hefty tab for those automatic, bigger-than-most cost-of-living increases is eased, Metro users as well as the transit jobholders themselves may find a rough road ahead.

Why is it up to the state legislatures? Current law, agreed to by Maryland, Virginia, the District and Congress, requires Metro and its unins to settle disputes through binding arbitration. As a result of the latest arbitration ruling last month, Metro's bus drivers and subway train operators get automatic raises four times a year that match the rate of inflation for the first nine percentage points, then match approximately two-thirds of each additional point. All this is guaranteed now -- and here's the rub -- regardless of the local jurisidictions' abilities to pay.

A change in the binding arbitration requirement can't happen unless the two states, the District and Congress all agree to it -- which brings us straight to Annapolis and Richmond, where the legislatures are in session now. Virginia state Sen. Adelard Brault (D-Fairfax) and Maryland state Sen. Thomas Patrick O'Reilly (D-Lanham) are pushing bills in their respective legislatures that would amend the law. Both legislatures operate part-time, and a good part of that part-time is lost already this year. Austerity, good sense and timing all dictate action in both capitals now, so the District Council and Congress can follow the lead before the costs of Metro get totally out of hand.