We recently undertook this trip when flying into Washington and were first of all amazed at the scattered information available online . We determined that a bus link between the city and the airport existed but the details were unclear and in fact even at the airport the information desk had to look up and call around to assist us.
So here you will find a description of the journey using public transportation, between Washington Dulles airport and the city as well as points along the way. The bus is punctual, clean and works perfectly. It is important to note you will need exactly $7.00 is USD to pay for a ticket in the bus from the machine which does not accept cards or make change.
From the Airport to the City
When you depart the arrivals terminal of Dulles, be sure to proceed out Door number 4. This is where you will find the bus stop outside. From the point of embarking the bus will make three stops: a nearby local stop, Rosslyn which is just outside D.C. and has a connection to the Blue line of the Metro (this line is currently closed for construction) and the final stop is L’Enfant Plaza Station. From here you can catch the yellow line to any other line or stop in D.C.
From the City to the Airport
To proceed from Washington to Dulles take any one of the three stops in reverse. The trickiest is the L’Enfant Plaza Station because it has several exits which proceed to side streets and some to the Metro. Certain passageways are closed off on weekends too.
The journey lasts around 45 minutes and even when it can be slightly longer in peak rush hours, but so would a taxi (which can cost $100 for the trip) or a shared shuttle van (which can cost $30 and you will have to stop at others hotels.)