SEVEN YEARS ago, the stakes were incredibly high as the Metrominds of regional transportation gathered for a most critical decision: Who should assume the stewardship of Greater Washington's most expensive, elaborate and essential joint public venture. From the beginning, the history of Metro had been a sequel to the "Perils of Pauline," with some new life-threatening political crisis every week for the subway system that constantly demanded the best engineering and political, bureaucratic and diplomatic skills available merely to move another mile down the tracks.

The acting general manager, assigned to run things until completion of a national and internal search for a successor, was a Washingtonian who had risen through the federal government from GS-2 clerk typist to acting director of civil rights at the Department of Transportation before moving to Metro as chief of administration. Carmen Turner had taken on the temporary assignment in the same way she had taken on every other duty -- without fanfare. In the course of discussion about a general manager, the Metro board members -- representatives of the participating elected governments -- began noting how well things had gone under the interim stewardship of Mrs. Turner. Come to think of it, she'd done beautifully -- and why not give her the job? They did -- and Carmen Turner proceeded to take Metro on its smoothest ride ever.

Now, after skillfully steering Metro through the political obstacles and against the financial odds -- from 42 miles and 47 stations of rail to 70 miles and 63 stations -- Mrs. Turner is leaving the system to assume the No. 2 position at the Smithsonian Institution, where managerial and financial problems and internal tensions will put her highly acclaimed management skills to yet another tough test. But if Mrs. Turner addresses them in the same unflappable, strong and responsive manner that she did those of Metro, the Smithsonian is in for better times.

Washington has been blessed with a special pool of skilled administrators who have risen without great fanfare to various top roles in difficult times -- and have done well. Mrs. Turner is high on this list. By the scope of her assignment, she had as well the additional responsibility of serving an entire region, two state governments, Congress and the president -- all partners in what has become a nationally acclaimed transportation system. She deserves big thanks.