21750.  The driver of a vehicle overtaking another vehicle or a
bicycle proceeding in the same direction shall pass to the left at a
safe distance without interfering with the safe operation of the
overtaken vehicle or bicycle, subject to the limitations and
exceptions hereinafter stated.



21751.  On a two-lane highway, no vehicle shall be driven to the
left side of the center of the roadway in overtaking and passing
another vehicle proceeding in the same direction unless the left side
is clearly visible and free of oncoming traffic for a sufficient
distance ahead to permit such overtaking and passing to be completely
made without interfering with the safe operation of any vehicle
approaching from the opposite direction.



21752.  No vehicle shall be driven to the left side of the roadway
under the following conditions:
   (a) When approaching or upon the crest of a grade or a curve in
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.
   (b) When the view is obstructed upon approaching within 100 feet
of any bridge, viaduct, or tunnel.
   (c) When approaching within 100 feet of or when traversing any
railroad grade crossing.
   (d) When approaching within 100 feet of or when traversing any
intersection.
   This section shall not apply upon a one-way roadway.



21753.  Except when passing on the right is permitted, the driver of
an overtaken vehicle shall safely move to the right-hand side of the
highway in favor of the overtaking vehicle after an audible signal
or a momentary flash of headlights by the overtaking vehicle, and
shall not increase the speed of his or her vehicle until completely
passed by the overtaking vehicle.  This section does not require the
driver of an overtaken vehicle to drive on the shoulder of the
highway in order to allow the overtaking vehicle to pass.



21754.  The driver of a motor vehicle may overtake and pass to the
right of another vehicle only under the following conditions:
   (a) When the vehicle overtaken is making or about to make a left
turn.
   (b) Upon a highway within a business or residence district with
unobstructed pavement of sufficient width for two or more lines of
moving vehicles in the direction of travel.
   (c) Upon any highway outside of a business or residence district
with unobstructed pavement of sufficient width and clearly marked for
two or more lines of moving traffic in the direction of travel.
   (d) Upon a one-way street.
   (e) Upon a highway divided into two roadways where traffic is
restricted to one direction upon each of such roadways.
   The provisions of this section 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.



21755.  The driver of a motor vehicle may overtake and pass another
vehicle upon the right only under conditions permitting such movement
in safety.  In no event shall such movement be made by driving off
the paved or main-traveled portion of the roadway.



21756.  (a) The driver of a vehicle overtaking any interurban
electric or streetcar stopped or about to stop for the purpose of
receiving or discharging any passenger shall stop the vehicle to the
rear of the nearest running board or door of such car and thereupon
remain standing until all passengers have boarded the car or upon
alighting have reached a place of safety, except as provided in
subdivision (b) hereof.
   (b) Where a safety zone has been establilshed or at an
intersection where traffic is controlled by an officer or a traffic
control signal device, a vehicle need not be brought to a stop before
passing any interurban electric or streetcar but may proceed past
such car at a speed not greater than 10 miles per hour and with due
caution for the safety of pedestrians.
   (c) Whenever any trolley coach or bus has stopped at a safety zone
to receive or discharge passengers, a vehicle may proceed past such
trolley coach or bus at a speed not greater than 10 miles per hour.



21757.  The driver of a vehicle shall not overtake and pass upon the
left, nor shall any driver of a vehicle drive upon the left side of,
any interurban electric or street car proceeding in the same
direction whether the street car is actually in motion or temporarily
at rest, except:
   (a) When so directed by a police or traffic officer.
   (b) When upon a one-way street.
   (c) When upon a street where the tracks are so located as to
prevent compliance with this section.



21758.  In the event any vehicle is being operated on any grade
outside of a business or residence district at a speed of less than
20 miles per hour, no person operating any other motor vehicle shall
attempt to overtake and pass such slow moving vehicle unless the
overtaking vehicle is operated at a speed of at least 10 miles per
hour in excess of the speed of the overtaken vehicle, nor unless the
passing movement is completed within a total distance not greater
than one-quarter of a mile.



21759.  The driver of any vehicle approaching any horse drawn
vehicle, any ridden animal, or any livestock shall exercise proper
control of his vehicle and shall reduce speed or stop as may appear
necessary or as may be signalled or otherwise requested by any person
driving, riding or in charge of the animal or livestock in order to
avoid frightening and to safeguard the animal or livestock and to
insure the safety of any person driving or riding the animal or in
charge of the livestock.