How to get to/from Washington Dulles International Airport?

Can you wait a couple of years? They’re extending the DC metro to the airport at the moment… The metro should reach Tyson’s Corner in 2013, and the airport a few years later (2018 is apparently the latest date).

If you don’t want to wait several years, it all depends how much of a hurry you’re in, and when you’re going. During peak hours, your best bet is to take the bus between the airport and
Rosslyn metro station, and the Orange line between the city and there. Traffic can get really bad on the freeway at peak times, so you can smugly speed past it on the metro. The bus ticket is $6 (exact change only), metro onwards is a few dollars depending on your destination, and the 5A timetable is here. I’ve done this myself, and I found it fine, even with a moderate size bag.

However, because of the work to extend the metro, evenings / weekends can see a lot of engineering work taking place on the Orange metro line. For those times, you’ll be better off taking a bus from downtown to the airport. There are both private and public ones, with differing costs / comfort. The MWAA site lists the various options

From next year, I think the best bet will be bus to Tyson’s Corner, then the new metro line into town.

Considerations:

• Dulles (like BWI) lies a considerable distance from the District; there are no "obvious" options because each involves a tradeoff of time or money. Only Reagan National (DCA) is truly convenient to the city.
• If you have a large party or many bags, a taxi may be worth the hassle. There is no place to store bags when using public transportation, and a single ride on Metro can involve six or seven escalators— which these days are often out of service.
• The Metro system is undergoing considerable construction and maintenance on evenings and weekends; at other times it can be quite crowded. This has negatively impacted its speed and reliability.

Silver Line Metro

After many decades of planning, politics, discussion, and delays, Washington’s Metro system has been extended to Ashburn, Virginia, including a dedicated Washington Dulles International Airport stop on the Silver Line.

The station is connected to the main terminal via an underground pedestrian tunnel accessed from the baggage claim level. Simply follow the signs. The station is around 600ft / 180m from the terminal and has moving walkways.

Board the Silver Line in the direction of Downtown Largo (eastbound) to head into Washington. The fare from the airport to Metro Center is currently $3.85 off-peak and $6.00 peak.

The opening of the Silver Line extension means that the Silver Line Express and Metrobus 5A services have been canceled. Fairfax Connector bus 952 to Reston and 983 to the Smithsonian Udvar-Hazy Air & Space Museum remain in operation

Taxis

The Washington Flyer Taxi has a monopoly on service to the airport and its rates are fixed (about $75 to Eastern Market plus surcharges and tips).

You can privately arrange for a different taxi or car service to pick you up, however, just as you might ask a friend or family member to pick you up. You can avoid the hassle of the taxi stand and maybe a few dollars as well, and if you come to Washington frequently, may be worth the investment of getting to know and keep a favorite driver.

Uber / Lyft

Uber and Lyft were made legal in Virginia in 2015. Prices vary considerably.

Shared Van

Another option is to take one of the shared van services like SuperShuttle. The vans make the most sense if you are traveling alone to a destination not well-served by Metro, but the rides can take a very, very long time if you are one of the later passengers to be dropped off. From Dulles, I generally only recommend this service for people traveling to the Virginia suburbs.

One-way car rental

Yet another option that makes sense for some is to rent a car from Dulles and return it to Reagan National the same day. Some rental agencies may waive the one-way fee on certain rate codes. If you have a good-sized party or many bags, this is sometimes an option. Of course, at least one person will need to take Metro or a taxi from Reagan National back to where you are in Eastern Market, and driving this route can be dicey during rush hours or if you are unfamiliar with the area.

When I was there last I used SuperShuttle. Its dead simple (just walk to their counter) and reasonably priced at about $30, if you are traveling in a group, additional passengers cost $10. Compared to taking a cab by yourself or with one other person, this saves a bundle.

Of course it is a shared shuttle service so it will take a bit longer than a cab ride, but it will get you all the way to your hotel. The only cheaper alternative is to take the bus to where the metro ends and take it into town. This will be cheaper but will likely take longer, especially if the metro does not stop close to your final destination.