The posted speed limit throughout the town is 25 miles per hour, even on streets where 35 miles per hour is a safe speed. The Upper Marlboro town police strongly enforce the speed limit. Beware exiting Route 4 (Pennsylvania Avenue) and going up Water Street at the edge of town. Although climbing the hill at 25 miles per hour may seem unrealistically slow, the police will give you a $70 ticket for going as much as 10 miles an hour over the limit.