A major expansion of the Central Intelligence Agency headquarters in McLean, announced last fall by the CIA, is expected to be approved next week by the National Capital Planning Commission.

Approval by the federal agency would be the first major hurdle for the project, which still must be funded by Congress. The expansion, expected to cost more than $100 million, would double the size of the CIA building, built in 1963, and bring an additional 3,000 employes to McLean from offices now scattered around Washington.

To ease traffic congestion, one of the major concerns of Fairfax County residents and officials, the CIA had announced it would stagger employe working hours and add only 1,000 new parking spaces at the complex, forcing many employes to carpool.

At an NCPC meeting last week, CIA officials said they favor major road improvements proposed by the Virginia Department of Highways and Transportation to improve access to the CIA from Rte. 123 (Dolley Madison Boulevard), including "flyover" (overhead) ramps, which would speed traffic "and have obvious advantages for us," said agency spokesman James McDonald.

McDonald told the commission that nearby residents were concerned about the ramps, however, and that the CIA would let Virginia highway officials take the lead in working out traffic improvements to Rte. 123 and the nearby intersection with Rte. 193 (Georgetown Pike). The federal government is expected to pay for the improvements, which county and NCPC officials said are needed.

"The CIA has been most cooperative, adjusting its plans and building heights and is in favor of road improvements," Fairfax Supervisor Nancy Falck said this week. "I think everything's working out very well."

Although some citizens had hoped the CIA might increase use of its George Washington Memorial Parkway entrance, Falck and NCPC officials said traffic on the parkway, particularly in the afternoon, already has reached the saturation point and could be increased very little. Falck said a redesigned exit ramp onto the parkway might improve merging, however.

Although the NCPC is expected to approve the master plan showing the general size and layout of the project, it still must give preliminary and final approval to the design, landscaping and specific plans.

Commission staff officials emphasized that that will give the commission two more opportunities to review the progress made on the traffic situation.