The executive committee of the American Trucking Associations has voted to move the trade group's headquarters to Alexandria, after 3 1/2 years of attempting to win District government approval to expand its downtown headquarters.

Although final papers on the move have not been signed, the group, which represents most of the nation's trucking industry, is planning to build a $12 million facility which would provide office space for about 500 employes near the Eisenhower Ave. Metro rail stop in Alexandria.

The decision to make the move is based on the association's failure to win city government approval for a major expansion of the association's headquarters near Dupont Circle. Neighborhood citizens' groups have fought the expansion of the facility.

The association headquarters, which also includes the offices of affiliated trucking conferences, is inadequate for the growing group, officials say. The association now uses other office sites in Rosslyn and in Northwest Washington to house staff members.

But the move is complicated by the fact that ATA is negotiating a complex land swap involving Gates Hudson Associates and the city of Alexandria. ATA would lease the land with an option to buy.

"It hurts me because I was the biggest advocate of staying here," said Donald Tender, ATA's managing director for finance. "But I started 3 1/2 years ago on this zoning situation with a full head of brown hair, and now it's turning grey."