TRANSPORTATION SECRETARY Brock Adams acted with class. He was a good team player for two and a half years. But the president misjudged the man if he assumed that Mr. Adams would react greatefully or compliantly to the declaration that he could stay at DOT only if he would just jettison some of his top staff. Mr. Adam's reply was that he, too, had a few points to get settled before he made up his mind.

The most refreshing aspect of his rejoinder was that it reached beyond conflicts of personnel and personalities to the issues on which Mr. Adams has felt most frustrated: promotion of mass transit and development of a more efficient automobile.

On both questions, Mr Adams has been very strong -- and very right. He drove this region's Metro system through the most searching reexamination that it has ever received -- because he wanted to ensure its success. For three years, too, he has been transit nationwide. Just last weekend it seemed that energy problems had finally brought Mr. Carter around to that view. Then on Monday, officials from the White House and the Office of Management and Budget made frantic last-minute efforts to get the $1.7-billion Metro financing bill deferred in the House. And by Wednesday, Mr. Adams had been told that the president's commitment to a new, $10-billion mass-transit program did not mean a $10-billion increase in transit aid after all. So once again the secretary had to go up to Capitol Hill and defend the administration's backing-off.

It is no wonder that Mr. Adams got fed up with White House bungling and the OMB's penny-wise approach. By spelling out the causes of his discontent, he has left Mr. Carter doubly on the spot. Apparently DOT, an increasingly vital and visible department, is now to be managed largely from the White House; the new acting secretary, W. Graham Clayton, is serving only in an interim role. So the burden is now on Mr. Carter to clarify not only how that arrangement is going to work -- but also what kinds of transportation policies are going to be pursued.