The Washington, DC area is served by three different airports. Some airlines may offer better prices into one airport than another. You may also find direct flights from one airport and not from another.
Here is a summary of some of the differences of each airport.
Washington National Airport (DCA)
Ronald Reagan Washington National Airport, commonly known as National Airport, is located in Arlington County, Virginia and is the closest airport to downtown Washington, DC. National Airport is the most convenient of the area airports for visitors staying in the heart of the city and residents who live in the downtown area. The airport is accessible by Metro. Take subway
from DCA to Union Station or NoMa/Gallaudet U Metro Station. During rush hour, National Airport can be difficult to get to, especially from the suburbs of Maryland and Virginia. A short runway limits the size of the aircraft that fly in and out of Washington (the largest is a 767), so the airport only offers domestic flights and a few flights to Canada and the Caribbean. Dulles International Airport (IAD)
Dulles International Airport is located 26 miles from Washington, DC in Chantilly, Virginia. The airport is about a 40-minute drive from downtown Washington, DC in non-rush hour traffic. The Dulles Airport Access Road makes the airport easy to get to once you get off of I-495. There are plenty of shuttles and taxis
to transport visitors around the region. Since Washington, DC traffic is often congested, you should plan ahead and avoid flight times near rush hour. Dulles is the first airport in the country to debut a system that automatically calculates wait times at the security checkpoints and displays them in real time. Since both mezzanines are connected beyond security, passengers have the option to select the line with the shorter wait. Baltimore-Washington International Airport (BWI)
Baltimore/Washington International Thurgood Marshall Airport, commonly known as BWI Airport, is located south of Baltimore. From the DC area, travel north on I-95 toward Baltimore to I-195. Take I-195 East (exit 47 off of I-95) toward BWI Airport. Follow the signs to the terminal. Southwest Airlines recently built a new terminal here and offers lots of flights at lower prices than some of its competitors. The MARC
train station is nearby offering train service to Union Station in Washington, DC from BWI Airport.