Washington Metropolitan Area Transit Authority (WMATA) provides subway service (Metrorail) in the District and in the Maryland suburbs. Maryland's Montgomery County is served by the system's busiest route, the Red Line, and Prince George's County is served by the Blue, Orange, and Green lines. It begins operation at 5 am on weekdays and 7 am on weekends and closes on weekdays at midnight and weekends at 3 am. During the weekday peak periods (5-9:30 am and 3-7 pm), trains come along every three to six minutes. At other times trains run about every 12 to 15 minutes.
The Metro's base fare is $1.60; the actual price rises depending on the time of day and the distance traveled. Up to two children under age five ride free with a paying passenger. Buy your ticket at the Farecard machines, some of which accept credit cards. One-day passes are $9 and seven-day passes are $47. Make sure you hang on to your Farecard—you need it to exit at your destination. Locals use the SmarTrip card, a plastic card that can hold any fare amount and can be used throughout the subway system. SmarTrip fares are 25¢ cheaper than using cash. Buy passes or SmarTrip cards at the Metro Center sales office.