A. 
Upon all roadways of sufficient width a vehicle shall be driven upon the right half of the roadway, but not upon the shoulder, except as follows:
1. 
When overtaking and passing another vehicle proceeding in the same direction under the rules governing such movement.
2. 
When an obstruction exists making it necessary to drive to the left of the center of the street, provided, any person so doing shall yield the right-of-way to all vehicles traveling in the proper direction upon the unobstructed portion of the street within such distance as to constitute an immediate hazard.
3. 
Upon a roadway restricted to one-way traffic.
B. 
Upon all roadways any vehicle proceeding at less than the normal speed of traffic at the time and place and under the conditions then existing shall be driven in the righthand lane then available for traffic, or as close as practicable to the righthand lane then available for traffic, or as close as practicable to the righthand curb or edge of the roadway, 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 driveway.
C. 
Upon any roadway having four or more lanes for moving traffic and providing for two-way movement of traffic, no vehicles shall be driven to the left of the centerline of the roadway, except when authorized by official traffic control devices designating certain lanes to the left side of center of the roadway for use by traffic not otherwise permitted to use such lanes, or except as permitted under subsection A.2 of this section. However, this subsection shall not be construed as prohibiting the crossing of the centerline in making a left turn into or from an alley, private road or driveway.
(CAC 9.16.010; AO No. 78-72)
Drivers of vehicles proceeding in opposite directions shall pass each other to the right, and, upon roadways having width for not more than one lane of traffic in each direction, each driver shall give to the other at least one-half of the main-traveled portion of the roadway as nearly as possible.
(CAC 9.16.020; AO No. 78-72)
A. 
The following rules shall govern the overtaking and passing of vehicles proceeding in the same direction, subject to those limitations, exceptions and special rules stated in this section:
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.
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 on audible signal and may not increase the speed of the vehicle until completely passed by the overtaking vehicle.
3. 
The driver of a motor vehicle overtaking a vulnerable road user proceeding in the same direction shall pass to the left at a safe distance, not less than three feet, and shall not return to drive on the right side of the roadway until safely clear of the overtaken vulnerable road user. The municipal traffic engineer may erect and maintain signage along public ways to notify operators of motor vehicles of the requirements for passing a vulnerable road user from a safe distance as required by this section.
(CAC 9.16.030; AO No. 78-72; AO No. 89-52; AO No. 2011-113(S), § 29, 11-22-2011, eff. 12-22-2011; AO No. 2023-65(S-1), § 4, 10-9-2023)
A. 
The driver of a vehicle may overtake and pass on 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. 
On a street with unobstructed pavement not occupied by parked vehicles of sufficient width for two or more lines of moving vehicles in each direction.
3. 
Upon a one-way street, or upon any roadway upon which traffic is restricted to one direction of movement where the roadway is free from obstruction and of sufficient width for two or more lines of moving vehicles.
B. 
The driver of a vehicle may overtake and pass another vehicle on the right only under conditions permitting such movement in safety. In no event shall such movement be made by driving:
1. 
Off the pavement on the shoulder;
2. 
Off the main-traveled portion of the roadway;
3. 
On or across a solid white line; or
4. 
In a lane designated by the municipal traffic engineer as a parking or bicycle lane.
(CAC 9.16.040; AO No. 78-72; AO No. 89-52; AO No. 2011-113(S), § 30, 11-22-2011, eff. 12-22-2011)
No vehicle may be driven to the left side of the center of the roadway in overtaking and passing another vehicle proceeding in the same direction unless authorized by the provisions of this title, and unless such left side is clearly visible and is free of oncoming traffic for a sufficient distance ahead to permit such overtaking and passing to be completely made without interfering with the operation of any vehicle approaching from the opposite direction or any vehicle overtaken. In every event, the overtaking vehicle must return to an authorized lane of travel as soon as practicable, and, if the passing movement involves the use of the lane authorized for vehicles approaching from the opposite direction, before coming within 200 feet of any approaching vehicle.
(CAC 9.16.050; AO No. 78-72)
A. 
No vehicle shall be driven on the left side of the roadway under the following conditions:
1. 
When approaching or upon the crest of a grade or a curve in the street when the driver's view is obstructed within such distance as to create a hazard if another vehicle might approach from the opposite direction; or
2. 
When approaching within 100 feet of or traversing any intersection or railroad grade crossing; or
3. 
When the view is obstructed upon approaching within 100 feet of any bridge, viaduct or tunnel; or
4. 
When in a designated school zone; or
5. 
When a single solid yellow line or two solid yellow lines are present.
B. 
The limitations set out in subsection A of this section shall not apply upon a one-way roadway, or under conditions described in section 9.16.010A.2, or to the driver of a vehicle turning left into or from an alley, private road, driveway or intersection.
(CAC 9.16.060; AO No. 78-72; AO No. 2011-113(S), § 32, 11-22-2011, eff. 12-22-2011)
A. 
The municipal traffic engineer is authorized to determine those portions of any street where overtaking and passing or driving to the left of the roadway would be especially hazardous and may by appropriate signs or markings on the roadway indicate the beginning and end of such zones, and, when such signs or markings are in place and clearly visible to an ordinarily observant person, every driver of a vehicle shall obey the direction thereof.
B. 
When signs or markings are in place and define a no passing zone as set forth in subsection A, no driver shall at any time drive on the left side of the roadway within such no passing zone or on the left side of any pavement striping designed to mark such no passing zone throughout its length, including two solid yellow lines or a broken yellow line with a solid yellow line.
C. 
This section does not apply under the conditions described in section 9.16.010A.2, nor to the driver of a vehicle turning left into or from an alley, private road, driveway or intersection.
(CAC 9.16.070; AO No. 78-72; AO No. 2011-113(S), § 33, 11-22-2011, eff. 12-22-2011)
A. 
The municipal traffic engineer may designate any one-way street or alley, and when so designated the traffic engineer shall place and maintain signs giving notice thereof, and no such regulation shall be effective unless such signs are in place. Signs indicating the direction of lawful traffic movement shall be placed at every intersection where movement of traffic in the opposite direction is prohibited.
B. 
Upon those streets and parts of streets and in those alleys designated as one-way, vehicular traffic shall move only in the designated direction when signs indicating the direction of traffic are erected and maintained at every intersection where movement in the opposite direction is prohibited.
C. 
The municipal traffic engineer is authorized to determine and designate streets, parts of streets or specific lanes thereon upon which vehicular traffic shall proceed in one direction during one period and the opposite direction during another period of the day, and shall place and maintain appropriate markings, signs, barriers or other devices to give notice thereof. The municipal traffic engineer may erect signs temporarily for designating lanes to be used by traffic moving in a particular direction, regardless of the centerline of the roadway.
D. 
It is unlawful for any person to operate any vehicle in violation of such markings, signs, barriers or other devices so placed in accordance with this title.
(CAC 9.16.080; AO No. 78-72)
Whenever a roadway is divided into two or more clearly marked lanes for traffic in one direction, the following rules shall apply:
A. 
A vehicle shall be driven as nearly as practicable within a single lane and shall not be moved from the lane until such movement may be made with reasonable safety, and properly signaled as required by section 9.22.040.
B. 
A single solid white line separating lanes of travel in the same direction may be crossed when such movement may be made with reasonable safety.
C. 
Crossing a double white line is prohibited.
D. 
Official signs approved by the traffic engineer 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.
E. 
Official signs approved by the traffic engineer may be erected directing vehicles in specified lanes to make specific turns or movements. Vehicles in these lanes shall make the turn or movement indicated by the device and shall not be moved right or left upon the roadway except to make the movement indicated by the traffic device.
F. 
Drivers of vehicles shall remain entirely within one lane and shall not initiate a lane change when approaching within 100 feet of or while traversing a signalized intersection.
(CAC 9.16.090; AO No. 78-72; AO No. 89-52; AO No. 94-68(S), § 6, 8-11-1994; AO No. 2011-113(S), § 34, 11-22-2011, eff. 12-22-2011)
A. 
The municipal traffic engineer may designate portions of any roadway for a bicycle lane, and when so designated shall by appropriate signs or markings on the roadway indicate such bicycle lanes.
B. 
When signs or markings are in place giving notice of the existence of any bicycle lane, it may be used by any vulnerable road user. It shall be unlawful for any person:
1. 
To travel on foot upon a bicycle lane.
2. 
To operate any vehicle, other than those defined as vulnerable road users, within a bicycle lane.
3. 
To ride or operate a bicycle within a bicycle lane in any direction except that permitted vehicular traffic traveling on the same side of the roadway; provided that persons legally in use of the bicycle lane may proceed either way along a lane where arrows appear on the surface of the lane designating two-way bicycle traffic.
4. 
To park a motor vehicle across or on a bicycle lane except to obtain emergency parking.
5. 
To drive a motor vehicle across a bicycle lane except after giving the right-of-way to all persons legally in use of the bicycle lane, consistent with section 9.18.060A.
6. 
To operate a motor vehicle, motor-driven cycle, or motorcycle upon a designated bicycle lane except to drive across it.
C. 
Vulnerable road users may continue to travel upon a sidewalk or the roadway, even when a marked bicycle lane is present, provided they do so in accordance with applicable provisions under this title and in manner that does not create a hazard to others.
(AO No. 2011-113(S), § 35, 11-22-2011, eff. 12-22-2011; AO No. 2023-65(S-1), § 4, 10-9-2023)
The driver of a motor vehicle shall not follow another vehicle more closely than is reasonable and prudent, having due regard to the speed of such vehicle and the traffic upon and the conditions of the street.
(CAC 9.16.100; AO No. 78-72; AO No. 89-52)
Whenever any street has been divided into two or more roadways by leaving an intervening space, or by physical barrier or clearly indicated dividing section so constructed as to impede vehicular traffic, every vehicle shall be driven only upon the righthand roadway unless directed or permitted to use another roadway by official traffic control devices or police officers. No vehicle may be driven over, across or within any such dividing space, barrier or section, except through an opening in such physical barrier or dividing section or space, or at a crossover or intersection as established, unless specifically prohibited.
(CAC 9.16.110; AO No. 78-72)
A. 
The traffic engineer may regulate or prohibit the use of any controlled access roadway by any class or kind of traffic which is found to be incompatible with the normal and safe movement of traffic.
B. 
The traffic engineer adopting any such prohibition shall erect and maintain official traffic control devices on the controlled access street on which such prohibitions are applicable, and when in place no person may disobey the restrictions stated on such devices.
(CAC 9.16.130; AO No. 78-72; AO No. 80-4)
A. 
A driver of a vehicle shall exercise due care to avoid colliding with any pedestrian upon any roadway and shall give warning by sounding the horn when necessary and shall exercise proper precaution upon observing any child or any obviously confused or incapacitated person upon a roadway.
B. 
Every driver of a vehicle shall exercise due care to avoid colliding with an animal, other traffic or fixed or moveable objects.
(AO No. 89-52; AO No. 94-68(S), § 7, 8-11-1994)
A. 
All traffic shall circumvent the raised center island of a mini traffic circle, moving to the right or in a counter-clockwise direction.
B. 
Traffic approaching a mini traffic circle shall yield the right-of-way to vehicles lawfully within the intersection.
C. 
A vehicle having more than two axles or overall length of 29 feet or greater, or a large vehicle which is unable to circumvent the mini traffic circle due to the vehicle's limited turning radius, may make a left turn in front of the raised center island and proceed after yielding the right-of-way to any vehicles within the mini traffic circle or approaching it so close thereto as to constitute an immediate hazard.
(AO No. 2011-113(S), § 36, 11-22-2011, eff. 12-22-2011)
A. 
When two vehicles enter or approach an intersection not controlled by an official traffic-control device, from different roadways at or approximately at the same time, the driver of the vehicle on the left shall yield the right-of-way to the vehicle on the right except as otherwise provided in this section.
B. 
A driver who stops and yields may proceed when a safe interval occurs, when other traffic in or near the intersection does not constitute an immediate hazard, and while exercising caution, irrespective of the "vehicle on the right" rule stated in section A. When so proceeding, other vehicles approaching or at the intersection shall yield.
C. 
The right-of-way rules in subsections A and B do not apply if the approach or entrance of a vehicle into an intersection is otherwise covered by traffic regulations.
D. 
A driver entering a roundabout shall yield to a vehicle on the circulating roadway in the roundabout.
E. 
A vehicle in front of another vehicle in a roundabout has the right-of-way over following vehicles. "In front of another vehicle in a roundabout" means the front bumper of a vehicle is ahead of the front bumper of another vehicle.
F. 
A driver may not change lanes in the roundabout or exit the roundabout until the movement may be made safely.
(AO No. 2011-113(S), § 37, 11-22-2011, eff. 12-22-2011)