Tysons Corner, in many ways already the second city of the Washington metropolis, is poised to become much bigger.
The volume of building in Northern Virginia's jumbled suburban hub of offices and malls could grow by half under existing county rules if a proposed Metrorail line is built. Assuming recent growth rates hold, that seems likely to continue the area's rapid ascendance as a commercial hub second only to downtown Washington.
Central City vs. Edge City: Landowners and developers are lobbying to permit even more development in Tysons Corner.
Now a powerful coalition of developers and civic leaders has formed to make the case for allowing Tysons Corner to expand beyond existing limits and become more like a traditional downtown, possibly doubling again its development potential.
If proponents of expansion are successful, the area would be altered not only in size but in character, with its largest developer, West Group, proposing to carve its sprawling holdings up into city blocks modeled after downtown Chicago.
Height limits around Metro stops could allow buildings up to 250 feet, which is lower than in Chicago but higher than in much of downtown Washington, where 160 feet is a typical maximum.
By virtue of Tysons Corner's size and prominence, the incipient debate over the expansion represents what may be the region's most significant test of the "smart growth" movement, which calls for focusing development into urban clusters around transit stops.
"Right now, Tysons Corner is the world's most successful office park," said William D. Lecos, president of the Fairfax County Chamber of Commerce. "What we want is a downtown."
The effort is already being challenged by some neighborhood groups, who fear that more building will exacerbate congestion on Northern Virginia's roads.
"What's going to happen to the surrounding communities when 10,000 new condominiums are built there?" asked Susan Turner, president of the McLean Citizens Association, who emphasized that the group's board had not taken a position. "Our roads are already absolutely jampacked."
She is skeptical that building near Metro stops would lessen traffic troubles, arguing that Metro's Orange Line in Northern Virginia, one of its most crowded, may not be able to accommodate more riders.
"Smart growth assumes that you have a high-functioning, high-capacity Metro system," she said. "We have an overloaded line that will only be overtaxed by the new development."
But the push to expand Tysons Corner has political momentum, with developers and civic leaders considering new roads and a grid pattern of streets intended to ease bottlenecks.
On Tuesday night, three members of the Fairfax County Board of Supervisors and a new Tysons committee, a citizens group, met to coordinate a study to determine how much more development can fit once the proposed Metro line reaches the crossroads that 50 years ago was largely pasture. The effort was initiated after a rush of 21 developer applications in the area.
And today, the Fairfax County Chamber of Commerce is convening a meeting of business and civic leaders at George Mason University to discuss what Tysons might become.