§ 20-88 OVERTAKING A VEHICLE ON THE RIGHT; WHEN PERMITTED.
   (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 turn;
      (2)   Upon a street or highway with unobstructed pavement, not occupied by parked vehicles, of sufficient width for one or more lines of vehicles moving in each direction; and
      (3)   Upon a one-way street or upon any roadway on which traffic is restricted to one direction of movement, where the roadway is free from obstructions and of sufficient width for two or more lines of moving vehicles.
   (B)   (1)   The driver of a vehicle may overtake and pass another vehicle upon the right only under conditions permitting the movement in safety.
      (2)   In no event shall movement be made by driving off the pavement or main-traveled portion of the roadway.
(47 O.S. § 11-304) (`90 Code, § 20-37)