The use of public transportation, including taxis, is recommended in Washington D.C. as on-street parking is limited and traffic is often heavy, see the Pentagon Map
Pentagon Metro Station Washington, DC has one of the nicest subway systems in the United States. It serves the entire District of Columbia plus the most populous Maryland and Virginia suburbs. The Metrorail runs from 5:00 A.M. to 11:30 P.M. (Monday-Thursday), 5:00 A.M. to midnight (Monday-Thursday), 5:00 A.M.to 3:00 A.M. Friday, 7:00 A.M.to 3:00 A.M. Saturday, and 7:00 A.M. to midnight Sunday. The time between trains varies from three to 20 minutes depending on the time of day and the rail line involved. The only major part of the District not served by Metrorail is Georgetown.
The fare for a trip is calculated based on the combination of the time of day (rush hour vs. non-rush hour), and the departure and destination station. Each station has a lighted sign near the SmarTrip Card vending machines that displays the Metro system map and the one-way fare to every other station in the system. You must purchase a SmarTrip Card from one of the vending machines before you may enter the station. The card should be held near or on the SmarTrip target on the faregate–the card can be scanned while inside a wallet or purse passing over the target. In the Metrorail system, using the card to activate the target will display the value remaining as the faregate opens, both when entering and exiting.
To reach the Pentagon via the public Metrorail system, take either the yellow or blue line to the Pentagon stop. Exit the Metro and take the escalator up to the Pentagon entrance. For Metrorail map and more information, visit the Washington Metropolitan Area Transit Authority web site.
Union Station is the main intercity railway station in Washington. It is well served by Amtrak from cities up and down the East coast. A Washington Metrorail station (Red Line) is also located there. The Pentagon is one line change (to the Yellow Line) and five Metro stops away. For more information, visit the AMTRAK web site.
Union Station is also served by weekday Maryland Rail Commuter (MARC) trains from Silver Spring, Kensington, Garrett Park, Rockville, Gaithersburg, Germantown, and suburbs further to the northwest. MARC service goes all the way to Martinsburg, West Virginia. MARC also runs two additional lines to the northeast. Their Penn Line goes all the way to Aberdeen, MD, northeast of Baltimore. MARC service is less frequent and more expensive than Metrorail service. Schedule and fare information can be obtained 24 hours a day by telephone from the MARC computer system at (800) 325-7245 or visit the Maryland Rail Commuter web site.
Crystal City and Union Station are both served by Virginia Rail Express. There are two lines, one serving Fredericksburg to the south and the other serving Manassas to the west. Schedule and fare information can be obtained from (703) 658-6200 or visit the Virginia Railway Express web site.
The Pentagon is about a 10 minute walk from the Pentagon City Mall parking garages and is accessed through a pedestrian tunnel. The entrance to the pedestrian tunnel is directly across Army Navy Drive from the Pentagon City Mall parking garage. When you exit the tunnel, look for signs to the Metro entrance. No shuttle service is provided to or from the Pentagon. There is a charge for parking at the mall.
Below are directions using the major arteries around the Washington Capital Beltway:
From the South: Use I-95/I-395 N toward Washington, DC. Take Exit 8C toward US-1 S/Pentagon City/Crystal City/Reagan Nat'l Airport. Keep right at the fork onto Army Navy Drive. Turn left at the first traffic light into the Pentagon City Mall parking garage.
From the West: Use I-66 E towards Washington. Eventually you will merge onto VA-110 S/Jefferson Davis Highway via Exit 75 toward Pentagon/Alexandria. Take the I-395 N/US-1 N ramp towards Washington. Keep left to take the ramp toward Pentagon City. Take a slight right onto Army Navy Drive. Once you cross over S Hayes Street, continue to the next traffic light and turn left into the Pentagon City Mall parking garage.
From the Northwest: Use I-270 S towards Washington. Keep right to take I-270-SPUR S toward I-270/Washington/I-495/Northern Virginia. I-270-SPUR S becomes I-495 S/Capital Beltway/I-495 OUTERLOOP (crossing into Virginia). Take the George Washington Memorial Parkway, Exit 43, towards Washington and continue South for about 10 miles. Take the Exit toward I-395/VA-27/Lyndon B. Johnson Memorial Grove/Pentagon. Merge onto Washington Blvd/VA-27 South toward I-395 S/Washington Blvd/Pentagon. Take the VA-244 W/Columbia Pike ramp toward the Navy Annex. Take a slight right onto VA-244 W/Columbia Pike. Turn left onto S Joyce St. Turn left onto Army Navy Drive. At the first traffic light, turn right into the Pentagon City Mall parking garage.
From the Northeast: Use MD-295 S toward Washington, DC. Merge onto US-50 W/New York Ave NE towards Washington (crossing into District of Columbia). Take I-395 S towards the tunnel (crossing into Virginia). Take the Washington Blvd exit, Exit 8A, toward VA-27/Carpool Staging Area/Pentagon South Parking/S Arlington Ridge Road. Keep left to take the Carpool Staging Area/Pentagon South Parking ramp. Take a slight right onto S Rotary Road. Turn right onto S Fern Street. Turn right onto Army Navy Drive. Turn left at the second traffic light into the Pentagon City Mall parking garage.
From the East: Use US-50 W/New York Ave NE until you enter Washington, DC (crossing into District of Columbia). Take I-395 S toward the tunnel (crossing into Virginia). Take the Washington Blvd, Exit 8A, toward VA-27/Carpool Staging Area/Pentagon South Parking/S Arlington Ridge Road. Keep left to take the Carpool Staging Area/Pentagon South Parking ramp. Take a slight right onto S Rotary Road. Turn right onto S Fern Street. Turn right onto Army Navy Drive. Turn left at the second traffic light into the Pentagon City Mall parking garage.