Title 40, Chapter 6, Section 43
(a) The driver of a vehicle may overtake and pass upon the right of
another vehicle only under the following conditions:
(1) When the vehicle overtaken is making or about to make a left
(2) Upon a street or highway with unobstructed pavement of
sufficient width for two or more lanes of moving vehicles in the
direction being traveled by the overtaking vehicle.
(b) If otherwise authorized, the driver of a vehicle may overtake
and pass another vehicle upon the right only under conditions
permitting such movement in safety. Such movement shall not be made
by driving off the roadway.