Maryland Statutes
Subtitle 3 - Driving on Right Side of Roadway; Overtaking and Passing; Use of Roadway
Section 21-308 - One-Way Highways and Roadways; Rotary Traffic Islands

(a)    (1)    The State Highway Administration may designate any highway or any separate roadway under its jurisdiction for one-way traffic and shall place appropriate signs giving notice of the designation.
        (2)    On a roadway designated and signposted for one-way traffic, a vehicle may be driven only in the direction designated.
    (b)    A vehicle passing around a rotary traffic island may be driven only to the right of the island.