Operator says traffic increased more than a third in March-June quarter.
Traffic continues summer decline, but road crews are active.
An accident on the outer loop of the Beltway at the Woodrow Wilson Bridge blocked multiple lanes and snarled traffic for several hours on Friday afternoon.
Ideas include converting the HOV lanes to express toll lanes.
Many Beltway commuters will welcome this move.
Outer loop lanes have reopened near Joint Base Andrews in Maryland.
Watch for lane closings in the Tysons area, and in D.C., Metro has late-night work on all lines.
Traffic is moving very slowly between University Boulevard and MD-355/Rockville Pike/Wisconsin Avenue in Montgomery County.
The speed limit is going to go up on the 495 Express Lanes later this month to 65 mph.
Slick roadways and high water could snarl traffic Friday morning as the storm works its way through the Washington area.