New traffic pattern soon at Fairfax County Parkway/Fair Lakes Parkway interchange
From VDOT's website:
On or about November 18, 2011, north and southbound Fairfax County Parkway traffic will be shifted onto the newly constructed Ramps A, B, C and D. New traffic signals will be in place an operational at Fair Lakes Parkway / Fairfax County Parkway and Monument Dr. / Fairfax County Parkway. To facilitate this traffic switch the following lane closures will be implemented beginning at 9 PM Friday November 18th, continuing into Saturday morning November 19th. Please expect delays and use alternate routes.
So...coupled with the upcoming traffic jam that occurs every year about this time (also known as "holiday" traffic), it looks like this will be a good place to avoid (if you can) until January.
Check out VDOT's project page at:
http://www.virginiadot.org/projects/northernvirginia/fairfax_county_parkway-fair_lakes.asp.