Metro changed the destinations of more than 70 bus routes in Northern Virginia yesterday but a month-long information campaign paid off in a minimum of confusion.

Many buses changed their major North Arlington terminal from Rosslyn to Ballston, the temporary end of the Orange Line subway which was opened last Dec. 1.

That meant thousands of Fairfax County and Arlington commuters who once transferred between bus and subway had to do so at a new terminal. Bus routes have been realigned after each of the subway extensions to reduce deuplicate service.

Frank Sweeten, of Fairfax City, said that his bus and subway trip to downtown Washington took 10 minutes longer using the Ballston station than it had when he transferred at Rosslyn, but, he said, "hopefully it will get better."

During the morning rush hour, bus drivers were uncertain where they should park in the new bus terminal atop the Ballston station. The problem was exacerbated by ice left over from the weekend snowstorm. Most of those problems had been worked out by the evening rush hour but Metro employes Earl Long and Butch Seay answered dozens of questions from people who wanted to know which bay their bus would be using after they emerged from the subway.

A few people tried to transfer at Rosslyn yesterday, only to find that the bus no longer stopped there. "Some of 'em are mad as hell," said station attendant Ben Boyd. "It'll be fine in a couple of days.'"