Maryland Transportation Section 21-304
(a)   Subject to the requirements of subsection (b) of this section, the driver of a vehicle may overtake and pass to the right of another vehicle only:
(1)   If the overtaken vehicle is making or about to make a left turn;
(2)   On a highway with unobstructed pavement not occupied by parked vehicles and wide enough for two or more lines of vehicles moving lawfully in the same direction as the overtaking vehicle; or
(3)   On any one-way roadway, if the roadway is free from obstruction and wide enough for two or more lines of moving vehicles.
(b)   The driver of a vehicle may overtake and pass another vehicle to the right only if it is safe to do so.
(c)   The movement described under subsection (b) of this section may not be made by driving off the roadway.