A major Washington developer has announced plans for a multi-million dollar condominium and office complex in the Crystal City area of south Arlington where residents have long complained of existing congestion.

Officials of the Charles E. Smith Co. Told an Arlington citizens group last week that the $200 million development, called "Airport City," would occupy a 50-acre site across the George Washington Parkway from National Airport and behind Crystal City, another Smith-built project.

Airport City, Smith executives told residents and county officials, would contain 600 luxury condominium units, 2 million square feet of office space and a 4,000-car garage. The site is now crossed by tracks belonging to the Richmond, Fredericksburg & Potomac Railroad, which would be moved east, roughly parallel to the George Washington Parkway.

The develompent would be the largest new-construction condominium project in Arlington history.

The 50-acre site is owned by the RF & P Railroad.

Smith Co. officials yesterday declined to discuss the Airport City proposal with a reporter, but county officials and south Arlington residents said they have been told the firm will file plans with the county zoning board within the next two weeks. The proposal must then be approved by The Arlington County Board.

County officials said yesterday the project would be the same size as Rosslyn, Arlington's financially successful high-rise commercial development located across Key Bridge from District. They said Airport City would be similar in architecture and building height to Crystal City, which contains many modernistic concrete and glass buildings that rise 12 to 16 stories.

News of the Smith Co. proposal yesterday drew criticism from citizen activists who claim traffic congestion in the area, particularly on Jefferson Davis Highway (Route 1), already is a serious problem.

"There's just no way that the road network can handle the additional traffic [generated by Airport City]," said Nancy Swain, a South Arlington activist.

In 1976 Swain led a citizens' group that sued to prevent the construction of Pentagon City, a massive 118-acre high-rise commercial development now under construction northwest of Airport City. The U.S. Supreme Court refused to consider an appeal of a lower court decision permitting that development to proceed.

"All this development is just having a catastrophic effect on the county in terms of traffic and will just result in even greater air pollution," said John H. Quinn Jr., another leader of the group that tried to block Pentagon City on precisely those grounds. "Today's long, long delays on Shirley Highway will become intolerable in the future, if Airport City is built," he said.

"Arlington planned for Crystal City as though Airport and Pentagon cities would not exist," added Quinn. He said he thought traffic congestion would be exacerbated because of the small road network in the area and because there are no immediate plans to widen Route 1.

"Airport City is going to dump a lot of traffic into Alexandria and onto the Parkway," said Swain.

In recent years, Alexandria and Interior Department officials have blocked another developer, Charles M. Fairchild Sr., from constructing a $300 million high-rise development along the Parkway in Alexandria.

"Alexandria seems to be so much more sensible in the development it will allow," said Swain. "I don't know why Arlington just encourages any kind of development it can get."

County officials who have approved high-rise developments such as Crystal City say they benefit the county by increasing its tax base, thereby offsetting the burden on the property tax.

Estimates show that a $200 million Airport City development could reap nearly $2.4 million per year in additional tax revenue.

"I haven't seen the plans yet," said County Board Chairman Walter L. Frankland Jr. yesterday, "but if Airport city is in keeping with the general theme of development and would contribute to the tax base without undue pressure on the existing community, I think it will fly."

The board it expected to consider the plan in May.

Knowledgeable Arlington officials said they thought the Smith Co. decided to develop the area -- despite the considerable cost of relocating the railroad tracks -- because of the enormous financial success of Crystal City. r

The proposed Airport City site is within a block of the Crystal City Metro station. The 600-unit condominium development presumably would appeal to those desiring housing close to mass transit and easily accessible to downtown Washington.

"Take a look at the county," said one official. "There is really no land left to develop except this parcel."