Rapid growth in the Fair Oaks-Fairfax Center area in the Route 50/66 corridor in the past two years has outpaced expectations, spurring the county planning staff to take a new, detailed look at its long-range land-use plan for the area.

The plan for the area was adopted only a few years ago after lengthy study by what was known as the 50/66 Task Force. The plan laid out specific details for development of a mix of major office, retail and commercial space and residential units designed to help protect existing single-family detached subdivisions.

But development is happening faster than the county anticipated, and some residents of neighborhoods the plan was designed to protect are having a change of heart about the future of their own homes.

Sidney R. Steele, acting director of the office of comprehensive planning, this week said that proposals for changes to the county's comprehensive land-use plan for the area include more than 600 acres of land.

"There are 26 items in the Fair Oaks area in the annual plan review," Steele said. "Those items have been pulled out of the normal annual plan review process for special consideration because of the numbers of changes involved," Steele said.

"It is time to take another look at the success of the 50/66 study," and time to examine nearby residential subdivisions, Steele said. "It is time to do an assessment of where we are going, to take stock of the plan."

Supervisor James Scott, whose magisterial district includes the Fair Oaks area, said he has been surprised by the speed of development.

"But given the location and the access, it makes sense," Scott said. The area is located in the I-66/Route 50 corridor near Route 29 with easy access to the Dulles International Airport.

In a reference to development taking place in the area, Scott said, "Quality does promote quality." The Hazel/Peterson Cos. are currently developing a 620-acre mixed-use project known as Fair Lakes. When completed, the development will include 1,321 residential units. Currently TRW is building a 120-acre campus-style office complex in Fair Lakes.

The Hazel/Peterson group this week broke ground for its own 130,000-square-foot corporate headquarters building, which will overlook a lake.

The Fairfax Board of Supervisors several weeks ago approved a major mixed-use project to include 12 buildings near Route 50 and West Ox Road to be built by the Centennial Development Corp. The 78-acre project will include housing, retail and office spaces and is being designed by the internationally known architect Welton Beckett.

Fairfax also recently approved a major office project for the Washington Corp. in the Fair Oaks area and an 1,800-unit town house development along the Tenderbrook Golf Course along the north side of Route 50.

Fairfax Supervisor Martha Pennino, considered by many to be the mother of the entire 50/66 complex, Thursday said she agrees the study of the area needs to be reviewed.

"Since there are so many challenges to the land plan , they need to be looked at together," she said.

Pennino says she does not think "we ought to up the density" of future development in the area. "We may need to up the money developers must contribute to the area's transportation fund to make sure that contributions keep up with money needed to make whatever transportation improvements will be needed in the future."

Pennino predicted that the Fairfax County Board of Supervisors this year will again study and vote on a proposal to move the Fairfax County government headquarters from its present site in the Massey Building in Fairfax City to 200 acres that the county owns in the middle of what has become the Fairfax Center area.

The number of amendments to the plan "signal that we need to look at it in detail," Steele said.

Scott said that the attitudes on the part of some area residents involved in attempts to get their own land use changed this year may represent significant changes in attitudes since the study was done.

Proposals for some changes in the Fairfax Farms subdivision "may or may not reflect the total community," Scott said. He said he thought changes proposed by residents of Cedar Lakes may be a consensus proposal.

Some of the challenges to the land include:

* Nine acres at the northwest corner of Walney Road and Poplar Tree Lane.

* Approximately 113 acres south of Route 50 west of West Ox Road.

* More than 200 acres at the intersection of Route 29 and Stringfellow Road.

* Thirty acres on Route 29 west of Shirley Gate Road.

* More than 115 acres between Stone Road, Big Rocky Run and Route 29.