UDC website with directions, campus map and to create custom directions can be found here.
Metro website has a trip planner and information about SmarTrip cards for Metro and buses.
From Dulles Airport:
Take the Dulles Toll Road to 495 towards Baltimore. Exit at Connecticut Avenue South. Drive about 9.5 km / 6 mi south on Connecticut Avenue, UDC is on the right-hand side, between Yuma Street and Van Ness Street.
Taking a bus or shuttle to Metro:
Go to Dulles bus shelter 2E to take the 5A bus (destination L’Enfant Plaza) and get off at the Rosslyn Metro Station. Board Metro Silver Line direction Largo Town Center and get off at Metro Center. Transfer to Red Line direction Shady Grove / Grosvenor to Van Ness Metro station at UDC campus.
Take the Silver Line shuttle for $5 from Arrivals Level Door 4. Get off at Wiehle-Reston East Metro station and board Silver Line in the direction of Largo Town Center, get off at Metro Center. Transfer to Red Line direction Shady Grove / Grosvenor to Van Ness Metro station at UDC campus.
From Washington Reagan National Airport:
(locals tend to call it National Airport, rather than Reagan)
Follow Route 1 North to the 14th Street Bridge. Take 14th Street, NW to K Street, NW. Turn left at K Street and follow it to Connecticut Avenue, getting on the service road to the right of the main road at or before 16th Street. Turn right onto Connecticut Avenue, heading north about 5.6 km / 3.5 mi to the UDC campus on the left-hand side at Van Ness Street.
From the National Airport Metro station, take the Yellow Line direction Greenbelt to Gallery Place, transfer to the Red Line direction Shady Grove / Grosvenor to Van Ness Metro station at UDC campus. Alternatively, take the Blue Line to Metro Center and transfer to Red Line to Van Ness.
From BWI Thurgood Marshall Airport:
Take the shuttle to the train station and take either the Amtrak train ($11) to Union Station in Washington, DC or the MARC train ($7) to Union Station. Board Metro Red Line in the direction of Shady Grove / Grosvenor and get off after eight stops at Van Ness Metro station at the UDC campus.
From Union Station:
Take the Red Line Metro in the direction of Shady Grove / Grosvenor and get off after eight stops at Van Ness Metro station at the UDC campus.