THEODORE C. LUTZ has always been a man of his word, but some months ago when he started talking about ending his service as general manager of Metro, nobody wanted to believe him. People still don't -- and neither do we. He has done a superb job. Never mind that this 33-year-old financial whiz feels "burned out" after 2 1/2 years of nonstop reorganizing and guiding the region's bus and subway system through a month of doomsdays, or that Ted Lutz feels a strong personal need to devote time to his wife and their 5-month-old boy; his political and administrative savvy is too important to lose at Metro. The Metro board was right in deferring action on his resignation, and the members should find a way to persuade Mr. Lutz to stay on beyond the April cutoff he has announced.

His ultimate decision, though, must be respected, however difficult finding a successor may prove to be. After all, it is thanks to Mr. Lutz that the Metro subway system still enjoys the local and federal support on which its precarious plans always depend. When he first came to Metro from the U.S. Department of Transportation (where, at 27, he was deputy undersecretary of transportation, one of the youngest people to hold such a high-level executive job), the subway plans were in jeopardy -- a restudy of all uncompleted lines had been ordered and there was significant local and federal support for truncating the 100-mile system. Mr. Lutz lobbied the local, state and federal governments hard for stop-gap financing to tide Metro over while long-term commitments were being negotiated.

Mr. Lutz also presided over the successful opening of 26 miles of subway routes; shifted Metro's organizational emphasis from subway construction to the operation of a combined bus-and-subway network; won support and money to open the subway at night and on Saturdays and handled problems ranging from subway breakdowns to construction accidents and a week-long wildcat strike by bus drivers. He even timed his resignation to allow completion of legislative sessions in Annapolis and Richmond, where Northern Virginia and suburban Maryland legislators are trying to win support for crucial financial aid for Mtro.

But much remains to be done -- by Mr. Lutz or his successor. More than $3 billion from various federal and local sources will be needed to finish building the subway; federal aid will hinge on local guarantees of operating funds; a clearly defined fare policy must be agreed to and some workable, permanent formula for sharing costs will have to be hammered out. These are challenges that demand someone with a thorough knowledge of the federal and regional government politics and bureaucracies -- and someone who doesn't mind following the hard act of Ted Lutz.