Metro is the second-busiest rapid transit system in the United States, and fifth-busiest in North America, in number of passenger trips, after the New York City Subway. There were 295 million trips on Metro in fiscal year 2018. In June 2008, Metro set a monthly ridership record with 19,729,641 trips, or 798,456 per weekday. Fares vary based on the distance traveled, the time of day, and the type of card used by the passenger. Riders enter and exit the system using a proximity card called SmarTrip.