Update 4:45: The Inner Loop has been re-opened but residual delays and congestion remain. Accident investigations continue at 495/Chain Bridge and 495/Arlington Blvd, according to Fairfax County.

Earlier: An accident on I-495 northbound at the Dulles Toll Road has closed the Inner Loop in the vicinity, according to Fairfax officials, and backups are extending past Route 66.

Expect heavy traffic and delays on north-south routes in eastern Fairfax and Tysons Corner, including routes 401/402, 425/427, and 462/463, officials say.

The Post’s new traffic page has live traffic cameras in the area that show that it’s slow going as of just before 4 p.m.