In Northern Virginia during weekday mornings, I-66 into Washington DC is HOV-2 only within the beltway. You can also take the Orange line on the Metro which fol

In Northern Virginia during weekday mornings, I-66 into Washington DC is HOV-2 only within the beltway. You can also take the Orange line on the Metro which follows 66. They are thinking about making it HOV-3 soon. If you don't carpool, you have to get off 66 before the beltway and take a longer route on roads with thicker traffic or take the metro which takes a bit longer. Parking in DC is an absolute nightmare unless you have a spot in a garage and those can cost $20+/day unless your employer pays for it.