Missouri Revised Statutes Title XIX. Motor Vehicles, Watercraft and Aviation § 304.016. Passing regulations--violations, penalties

(1) The driver of a vehicle overtaking another vehicle proceeding in the same direction shall pass to the left thereof at a safe distance and shall not again drive to the right side of the roadway until safely clear of the overtaken vehicle; and

(2) Except when overtaking and passing on the right is permitted, the driver of an overtaken vehicle shall give way to the right in favor of the overtaking vehicle and shall not increase the speed of such driver's vehicle until completely passed by the overtaking vehicle.

(1) When the vehicle overtaken is making or about to make a left turn;

(2) Upon a city street with unobstructed pavement of sufficient width for two or more lines of vehicles in each direction;

(3) Upon a one-way street;

(4) Upon any highway outside of a city with unobstructed pavement of sufficient width and clearly marked for four or more lines of traffic. The driver of a motor vehicle may overtake and pass another vehicle upon the right only under the foregoing conditions when such movement may be made in safety. In no event shall such movement be made by driving off the paved or main traveled portion of the roadway. The provisions of this subsection shall not relieve the driver of a slow-moving vehicle from the duty to drive as closely as practicable to the right-hand edge of the roadway.

(1) When approaching the crest of a grade or upon a curve of the highway where the driver's view is obstructed within such distance as to create a hazard in the event another vehicle might approach from the opposite direction;

(2) When the view is obstructed upon approaching within one hundred feet of any bridge, viaduct, tunnel or when approaching within one hundred feet of or at any intersection or railroad grade crossing.