Maryland Code, Transportation § 21-506

(a) Where a sidewalk is provided, a pedestrian may not walk along and on an adjacent roadway.

(b) Where a sidewalk is not provided, a pedestrian who walks along and on a highway may walk only on the left shoulder, if practicable, or on the left side of the roadway, as near as practicable to the edge of the roadway, facing any traffic that might approach from the opposite direction.