Metro

The heart of Washington DC's public transportation is the MetroRail system.  It provides service to the entire metro area and has numerous stations within walking distance of museums, monuments and other places of interest to tourists.  It’s generally safe, clean (though not as clean as it used to be) and easy to use, and it has reasonable fares.  On weekdays it operates from 5:30 a.m. to midnight, and on the weekends from 7:00 a.m. to 3:00 a.m.  Trains typically arrive every 6 to 12 minutes, though it may be longer during non-rush hours and weekends.  Large and helpful rail system and street maps are posted at each station, which makes navigation easy even for first-time visitors.  Look for large-print system maps near the Station Master's kiosk. Station Masters are very helpful if you're not sure how to use the system. Single fares start at $1.70, One Day Passes are available for $14 and 7-Day Fast Passes are available for $57.50.  Farecards can be purchased at any station.   After using your farecard to enter the station, be sure to hang on to it, as you will also need it to exit at your destination.  On Metrorail, trips taken with a SmarTrip® card cost $1 less those taken with a paper farecard (or, there's a $1 surcharge for trips taken on a paper card, which are the ones available to most tourists since you cannot buy a smart card at most metro stations in the city or the close-in suburbs).   Most stations are underground with escalator and elevator access, and they are marked above ground by a large letter M. As a matter of courtesy to others, stand to the right on escalators so that people can walk by you on the left. Laws prohibiting smoking and eating are strictly enforced throughout the system (even on outside platforms).

MetroBus

Coupled with the MetroRail system is the MetroBus system.   Its hours and fares are similar to the MetroRail’s.  While it’s a bit harder to use than the rail system, it does provide access to places around the city that don’t have a rail station in close proximity.   While tourists should find the rail stations to be sufficient for getting to attractions of interest, some business travelers may find that the bus stops are more convenient.  Bus stops are marked by red, white and blue signs, and they typically have route and schedule information posted.  Use a farecard or exact change.

SmartTrip Card

You can also purchase a stored-value SmartTrip card at any Metro station where parking is available, but not at all stations, or through Metro's web site and at Metro sales offices, using cash or a credit card.  Although the cards cost $5, they can be replaced free of charge if lost or stolen, provided you registered it.  You can use the SmartTrip cards on Metrorail and Metrobus equally, and the SmartTrip card will automatically give you a discount if you're transferring from the rail to the bus.  You'll also need a SmartTrip card to exit from any Metro parking lot. Seniors (over 65) can purchase a WMATA Senior ID card which allows them to purchase a Senior SmarTrip card.

The SmartTrip card can also be aboard  the DC Circulator buses.  The Circulator fare is only $1 (or free with a MetroBus transfer and half price for seniors).  The Georgetown-Union Station bus route runs between UnionStation and Georgetown (with the Convention Center as the center point), and the Convention Center - SW Waterfront bus route runs between the Convention Center and the Waterfront, with stops near the National Archive, the FBI Museum, the National Mall, and the Air and Space Museum). The Smithsonian - National Gallery of Art Loop bus route circles the National Mall.

 The fares are cheaper than MetroRail, but the bus runs along city streets and can take a while to get across town during rush hour (it could take 45 minutes to get from Union Station to Farragut Square on a rainy evening, when the MetroRail could take only 15 minutes). Buses start at 9:30 a.m. and arrive at intervals of five to ten minutes. Look for them at bus stops displaying the Circulator flag sign. You can get off and reboard free for a two-hour period if you use the transfer you can ask  for when you first board. Pick up a map when you board. Because there are so many stops, you can often get closer to your destination than with the Metro. Buses do not stop unless requested, so during the day travel times can be fast, while during rush hour local commuters cause it to stop frequently. Circulators are also wheel-chair accessible and have a few seats at floor level available for seniors and those with disabilities.