21650. Upon all highways, a vehicle shall be driven upon the right
half of the roadway, except as follows:
(a) When overtaking and passing another vehicle proceeding in the
same direction under the rules governing that movement.
(b) When placing a vehicle in a lawful position for, and when the
vehicle is lawfully making, a left turn.
(c) When the right half of a roadway is closed to traffic under
construction or repair.
(d) Upon a roadway restricted to one-way traffic.
(e) When the roadway is not of sufficient width.
(f) When the vehicle is necessarily traveling so slowly as to
impede the normal movement of traffic, that portion of the highway
adjacent to the right edge of the roadway may be utilized temporarily
when in a condition permitting safe operation.
(g) This section does not prohibit the operation of bicycles on
any shoulder of a highway, where the operation is not otherwise
prohibited by this code or local ordinance.
21650.1. A bicycle operated on a roadway, or the shoulder of a
highway, shall be operated in the same direction as vehicles are
required to be driven upon the roadway.
21651. (a) Whenever a highway has been divided into two or more
roadways by means of intermittent barriers or by means of a dividing
section of not less than two feet in width, either unpaved or
delineated by curbs, double-parallel lines, or other markings on the
roadway, it is unlawful to do either of the following:
(1) To drive any vehicle over, upon, or across the dividing
(2) To make any left, semicircular, or U-turn with the vehicle on
the divided highway, except through an opening in the barrier
designated and intended by public authorities for the use of vehicles
or through a plainly marked opening in the dividing section.
(b) It is unlawful to drive any vehicle upon a highway, except to
the right of an intermittent barrier or a dividing section which
separates two or more opposing lanes of traffic. Except as otherwise
provided in subdivision (c), a violation of this subdivision is a
(c) Any willful violation of subdivision (b) which results in
injury to, or death of, a person shall be punished by imprisonment in
the state prison, or imprisonment in a county jail for a period of
not more than six months.
21652. When any service road has been constructed on or along any
public highway and the main thoroughfare of the highway has been
separated from the service road, it is unlawful for any person to
drive any vehicle into the main thoroughfare from the service road or
from the main thoroughfare into the service road except through an
opening in the dividing curb, section, separation, or line.
21654. (a) Notwithstanding the prima facie speed limits, any
vehicle proceeding upon a highway at a speed less than the normal
speed of traffic moving in the same direction at such time shall be
driven in the right-hand lane for traffic or as close as practicable
to the right-hand edge or curb, except when overtaking and passing
another vehicle proceeding in the same direction or when preparing
for a left turn at an intersection or into a private road or
(b) If a vehicle is being driven at a speed less than the normal
speed of traffic moving in the same direction at such time, and is
not being driven in the right-hand lane for traffic or as close as
practicable to the right-hand edge or curb, it shall constitute prima
facie evidence that the driver is operating the vehicle in violation
of subdivision (a) of this section.
(c) The Department of Transportation, with respect to state
highways, and local authorities, with respect to highways under their
jurisdiction, may place and maintain upon highways official signs
directing slow-moving traffic to use the right-hand traffic lane
except when overtaking and passing another vehicle or preparing for a
21655. (a) Whenever the Department of Transportation or local
authorities with respect to highways under their respective
jurisdictions determines upon the basis of an engineering and traffic
investigation that the designation of a specific lane or lanes for
the travel of vehicles required to travel at reduced speeds would
facilitate the safe and orderly movement of traffic, the department
or local authority may designate a specific lane or lanes for the
travel of vehicles which are subject to the provisions of Section
22406 and shall erect signs at reasonable intervals giving notice
(b) Any trailer bus, except as provided in Section 21655.5, and
any vehicle subject to the provisions of Section 22406 shall be
driven in the lane or lanes designated pursuant to subdivision (a)
whenever signs have been erected giving notice of that designation.
Except as otherwise provided in this subdivision, when a specific
lane or lanes have not been so designated, any of those vehicles
shall be driven in the right-hand lane for traffic or as close as
practicable to the right edge or curb. If, however, a specific lane
or lanes have not been designated on a divided highway having four or
more clearly marked lanes for traffic in one direction, any of those
vehicles may also be driven in the lane to the immediate left of
that right-hand lane, unless otherwise prohibited under this code.
When overtaking and passing another vehicle proceeding in the same
direction, the driver shall use either the designated lane, the lane
to the immediate left of the right-hand lane, or the right-hand lane
for traffic as permitted under this code.
This subdivision does not apply to a driver who is preparing for a
left- or right-hand turn or who is entering into or exiting from a
highway or to a driver who must necessarily drive in a lane other
than the right-hand lane to continue on his or her intended route.
21655.3. (a) A high-occupancy vehicle lane on a state highway that
has been given permanent operational status as a high-occupancy lane
by the department on or after January 1, 1987, but before December
31, 1987, in conjunction with a transportation planning agency, and
that is operated as a high-occupancy vehicle lane on a 24-hour basis
after that date, shall be separated from adjacent mixed-flow lanes by
a buffer area of at least four feet in width.
(b) The transportation planning agency having within its area of
jurisdiction a high-occupancy vehicle lane meeting the operational
requirements of subdivision (a) and having no buffer or a buffer less
than four feet in width shall, by July 1, 1988, do one of the
(1) Enter into an agreement with the department to provide a
four-foot buffer between the high-occupancy vehicle lane and the
adjacent lanes and agree to pay any costs for the buffer not
programmed by the department.
(2) Submit to the department a written request that the
high-occupancy vehicle lane be changed to a mixed-flow lane.
(c) Upon receipt of notification by the transportation planning
agency of its request that the high-occupancy vehicle lane become a
mixed-flow lane, the department shall proceed with the work necessary
to change the high-occupancy lane to a mixed-flow lane.
(d) The width of a buffer between a high-occupancy vehicle lane
and adjacent lanes may be less than four feet at locations where a
four-foot buffer would require the removal, relocation, or
reconstruction of any existing bridge support structures or where
part of the buffer space is required for enforcement refuge areas.
21655.5. (a) The Department of Transportation and local
authorities, with respect to highways under their respective
jurisdictions, may authorize or permit exclusive or preferential use
of highway lanes for high-occupancy vehicles. Prior to establishing
the lanes, competent engineering estimates shall be made of the
effect of the lanes on safety, congestion, and highway capacity.
(b) The Department of Transportation and local authorities, with
respect to highways under their respective jurisdictions, shall place
and maintain, or cause to be placed and maintained, signs and other
official traffic control devices to designate the exclusive or
preferential lanes, to advise motorists of the applicable vehicle
occupancy levels, and, except where ramp metering and bypass lanes
are regulated with the activation of traffic signals, to advise
motorists of the hours of high-occupancy vehicle usage. No person
shall drive a vehicle upon those lanes except in conformity with the
instructions imparted by the official traffic control devices. A
motorcycle, a mass transit vehicle, or a paratransit vehicle that is
clearly and identifiably marked on all sides of the vehicle with the
name of the paratransit provider may be operated upon those exclusive
or preferential use lanes unless specifically prohibited by a
traffic control device.
(c) When responding to an existing emergency or breakdown in which
a mass transit vehicle is blocking an exclusive or preferential use
lane, a clearly marked mass transit vehicle, mass transit supervisor'
s vehicle, or mass transit maintenance vehicle that is responding to
the emergency or breakdown may be operated in the segment of the
exclusive or preferential use lane being blocked by the mass transit
vehicle, regardless of the number of persons in the vehicle
responding to the emergency or breakdown, if both vehicles are owned
or operated by the same agency, and that agency provides public mass
(d) For purposes of this section, a "paratransit vehicle" is
defined in Section 462.
(e) For purposes of this section, a "mass transit vehicle" means a
transit bus regularly used to transport paying passengers in mass
(f) It is the intent of the Legislature, in amending this section,
to stimulate and encourage the development of ways and means of
relieving traffic congestion on California highways and, at the same
time, to encourage individual citizens to pool their vehicular
resources and thereby conserve fuel and lessen emission of air
(g) The provisions of this section regarding mass transit vehicles
and paratransit vehicles shall only apply if the Director of
Transportation determines that the application will not subject the
state to a reduction in the amount of federal aid for highways.
21655.6. (a) Whenever the Department of Transportation authorizes
or permits exclusive or preferential use of highway lanes for
high-occupancy vehicles on any highway located within the territory
of a transportation planning agency, as defined in Section 99214 of
the Public Utilities Code, or a county transportation commission, the
department shall obtain the approval of the transportation planning
agency or county transportation commission prior to establishing the
exclusive or preferential use of the highway lanes.
(b) If the department authorizes or permits additional exclusive
or preferential use of highway lanes for high-occupancy vehicles on
that portion of State Highway Route 101 located within the boundaries
of the City of Los Angeles, the department shall obtain the approval
of the Los Angeles County Transportation Commission by at least a
two-thirds majority vote of the entire membership eligible to vote
prior to establishing the additional exclusion or preferential use of
the highway lanes.
(c) If the department restricts or requires the restriction of the
use of any lane on any federal-aid highway in the unincorporated
areas of Alameda County to high-occupancy vehicles, the Metropolitan
Transportation Commission shall review the use patterns of those
lanes and shall determine if congestion relief is being efficiently
achieved by the creation of the high-occupancy vehicle lanes. The
commission shall report its findings and recommendations in its HOV
Master Plan Update for the San Francisco Bay area no later than two
years after those high-occupancy vehicle lanes become operational.
21655.7. A local authority, with respect to any highway under its
jurisdiction, may authorize or permit a portion of the highway to be
used exclusively for a public mass transit guideway.
21655.8. (a) Except as required under subdivision (b), when
exclusive or preferential use lanes for high-occupancy vehicles are
established pursuant to Section 21655.5 and double parallel solid
lines are in place to the right thereof, no person driving a vehicle
may cross over these double lines to enter into or exit from the
exclusive or preferential use lanes, and entrance or exit may be made
only in areas designated for these purposes or where a single broken
line is in place to the right of the exclusive or preferential use
(b) Upon the approach of an authorized emergency vehicle
displaying a red light or siren, as specified in Section 21806, a
person driving a vehicle in an exclusive or preferential use lane
shall exit that lane immediately upon determining that the exit can
be accomplished with reasonable safety.
(c) Raised pavement markers may be used to simulate painted lines
described in this section.
21655.9. (a) Whenever the Department of Transportation authorizes
or permits exclusive or preferential use of highway lanes or highway
access ramps for high-occupancy vehicles pursuant to Section 21655.5,
the use of those lanes or ramps shall also be extended to vehicles
that are issued distinctive decals, labels, or other identifiers
pursuant to Section 5205.5 regardless of vehicle occupancy or
(b) No person shall drive a vehicle described in subdivisions (a)
and (b) of Section 5205.5 with a single occupant upon a
high-occupancy vehicle lane pursuant to this section unless the
decal, label, or other identifier issued pursuant to Section 5205.5
are properly displayed on the vehicle, and the vehicle registration
described in Section 5205.5 is with the vehicle.
(c) No person shall operate or own a vehicle displaying a decal,
label, or other identifier, as described in Section 5205.5, if that
decal, label, or identifier was not issued for that vehicle pursuant
to Section 5205.5. A violation of this subdivision is a misdemeanor.
(d) This section shall remain in effect only until January 1, 2008,
and as of that date is repealed, unless a later enacted statute,
that is enacted before January 1, 2008, deletes or extends that date.
21656. On a two-lane highway where passing is unsafe because of
traffic in the opposite direction or other conditions, a slow-moving
vehicle, including a passenger vehicle, behind which five or more
vehicles are formed in line, shall turn off the roadway at the
nearest place designated as a turnout by signs erected by the
authority having jurisdiction over the highway, or wherever
sufficient area for a safe turnout exists, in order to permit the
vehicles following it to proceed. As used in this section a
slow-moving vehicle is one which is proceeding at a rate of speed
less than the normal flow of traffic at the particular time and
21657. The authorities in charge of any highway may designate any
highway, roadway, part of a roadway, or specific lanes upon which
vehicular traffic shall proceed in one direction at all or such times
as shall be indicated by official traffic control devices. When a
roadway has been so designated, a vehicle shall be driven only in the
direction designated at all or such times as shall be indicated by
traffic control devices.
21658. Whenever any roadway has been divided into two or more
clearly marked lanes for traffic in one direction, the following
(a) A vehicle shall be driven as nearly as practical entirely
within a single lane and shall not be moved from the lane until such
movement can be made with reasonable safety.
(b) Official signs may be erected directing slow-moving traffic to
use a designated lane or allocating specified lanes to traffic
moving in the same direction, and drivers of vehicles shall obey the
directions of the traffic device.
21659. Upon a roadway which is divided into three lanes a vehicle
shall not be driven in the extreme left lane at any time, nor in the
center lane except when overtaking and passing another vehicle where
the roadway ahead is clearly visible and the center lane is clear of
traffic within a safe distance, or in preparation for a left turn, or
where the center lane is at the time allocated exclusively to
traffic moving in the direction the vehicle is proceeding and is
signposted to give notice of such allocation. This section does not
apply upon a one-way roadway.
21660. Drivers of vehicles proceeding in opposite directions shall
pass each other to the right, and, except when a roadway has been
divided into traffic lanes, each driver shall give to the other at
least one-half of the main traveled portion of the roadway whenever
21661. Whenever upon any grade the width of the roadway is
insufficient to permit the passing of vehicles approaching from
opposite directions at the point of meeting, the driver of the
vehicle descending the grade shall yield the right-of-way to the
vehicle ascending the grade and shall, if necessary, back his vehicle
to a place in the highway where it is possible for the vehicles to
21662. The driver of a motor vehicle traveling through defiles or
canyons or upon mountain highways shall hold the motor vehicle under
control at all times and shall do the following when applicable:
(a) If the roadway has no marked centerline, the driver shall
drive as near the right-hand edge of the roadway as is reasonably
(b) If the roadway has insufficient width to permit a motor
vehicle to be driven entirely to the right of the center of the
roadway, the driver shall give audible warning with the horn of the
motor vehicle upon approaching any curve where the view is obstructed
within a distance of 200 feet along the highway.
21663. Except as expressly permitted pursuant to this code,
including Sections 21100.4 and 21114.5, no person shall operate or
move a motor vehicle upon a sidewalk except as may be necessary to
enter or leave adjacent property.
21664. It is unlawful for the driver of any vehicle to enter or
exit any freeway which has full control of access and no crossings at
grade, except upon a designated on ramp with respect to entering the
freeway or a designated off ramp with respect to exiting the