Route 51X circulates around Upper Marlboro from the County Administration Building to the
County Courthouse and the Equestrian Center Park and Ride.
Effective December 4, 2023, Route 51X operates in staggered headways throughout the day: every
5 minutes from 6:00 to 9:00 a.m., every 7-8 minutes from 9:00 a.m. to 2:00 p.m., and every 10
minutes from 2:00 p.m. to 6:00 p.m. Additionally, the route starts and ends behind the County
Administration Building, rather than the Equestrian Center Park and Ride.