The operator of any vehicle shall obey the instructions of any official traffic-control device applicable thereto placed in accordance with the traffic regulations of the city, unless otherwise directed by a police officer, subject to the exceptions granted the driver of an authorized emergency vehicle when responding to emergency calls.
(Code 1957, § 6032)
No provision of the vehicle code or of this chapter for which signs are required shall be enforced against an alleged violator unless appropriate legible signs are in place giving notice of such provisions of the traffic laws.
(Code 1957, § 6032.1)
The city traffic engineer is hereby authorized to remove, relocate or discontinue the operation of any traffic-control device not specifically required by the vehicle code or this chapter whenever he shall determine in any particular case that the conditions which warranted or required the installation no longer exist or obtain.
(Code 1957, § 6036)
The city traffic engineer shall determine the hours and days during which any traffic-control device shall be in operation or be in effect, except those cases where such hours or days are specified in this chapter.
(Code 1957, § 6037)
The city traffic engineer shall have the power and duty to place and maintain official traffic-control devices when and as required under the traffic ordinances or resolutions of the city to make effective the provisions of such ordinances or resolutions.
(Code 1957, § 6031)
Whenever the vehicle code of the state requires for the effectiveness of any provision thereof that traffic-control devices be installed to give notice to the public of the application of such law, the city traffic engineer is hereby authorized to install the necessary devices, subject to any limitations or restrictions set forth in the laws applicable thereto.
(Code 1957, § 6031.1)
The city traffic engineer may also place and maintain such additional traffic-control devices as he may deem necessary or proper to regulate traffic or guide or warn traffic, but he shall make such determination only upon the basis of traffic engineering principles and traffic investigations and in accordance with such standards, limitations and rules as may be set forth in the traffic ordinances of the city or as may be determined by ordinance or resolution of the council.
(Code 1957, § 6031.2)
Whenever any ordinance or resolution of the city designates and describes any street or portion thereof as a through street or any intersection at which vehicles are required to stop at one or more entrances thereto, or any railroad grade crossing at which vehicles are required to stop, the city traffic engineer shall erect and maintain stop signs as follows:
(1) 
Location of signs. A stop sign shall be erected on each and every street intersecting such through street or portion thereof so designated, at those entrances of other intersections where a stop is required, and at any railroad grade crossing so designated.
(2) 
Conformance to vehicle code. Every such sign shall conform with, and shall be placed as provided in the vehicle code.
(Code 1957, § 6041)
Whenever the city traffic engineer shall determine that an emergency traffic congestion is likely to result from the holding of public or private assemblages, gatherings or functions, or for other reasons, he shall have power and authority to order temporary signs to be erected or posted indicating that the operation, parking or standing of vehicles is prohibited on such streets and alleys as he shall direct during the time such temporary signs are in place.
(Code 1957, § 6065.4)
Signs erected or posted pursuant to section 28-94 shall remain in place only during the existence of such emergency and the city traffic engineer shall cause such signs to be removed promptly thereafter.
(Code 1957, § 6065.41)
(a) 
The city traffic engineer shall establish, designate and maintain crosswalks at intersections and other places by appropriate devices, marks or lines upon the surface of the roadway as follows:
Crosswalks shall be established and maintained within the central traffic district and at such intersections outside such district and at such other places within or without such district where the city traffic engineer determines that there is particular hazard to pedestrians crossing the roadway, subject to the limitations contained in subsection (b) of this section.
(b) 
Other than crosswalks at intersections, no crosswalks shall be established at any block which is less than 400 feet in length and such crosswalk shall be located as nearly as practicable at midblock.
(c) 
The city traffic engineer may place signs at or adjacent to an intersection in respect to any cross-walk directing that pedestrians shall not cross in the crosswalk so indicated.
(Code 1957, § 609.51)
Whenever any ordinance or resolution of the city designates and describes any street or portion thereof as a street the use of which is permitted by any vehicle exceeding a maximum gross weight limit of three tons, the city traffic engineer is hereby authorized to designate such street by appropriate signs as "Truck Routes" for the movement of vehicles exceeding a maximum gross weight limit of three tons.
(Code 1957, § 6094)
Whenever any ordinance or resolution of the city designates and describes any street or portion thereof as a street the use of which is prohibited by any commercial vehicle, the city traffic engineer shall erect and maintain appropriate signs on those streets affected by such ordinance.
(Code 1957, § 6095)
Whenever any ordinance or resolution of the city designates any one-way street or alley, the city traffic engineer shall place and maintain signs giving notice thereof.
(Code 1957, § 6097)
Signs indicating the direction of lawful traffic movement shall be placed at every intersection where movement of traffic in the opposite direction is prohibited.
(Code 1957, § 6097.2)
The city traffic engineer is hereby directed to install and maintain official traffic signals at those intersections and other places where traffic conditions are such as to require that the flow of traffic be alternately interrupted and released in order to prevent or relieve traffic congestion or to protect life or property from exceptional hazard.
(Code 1957, § 6033)
The city traffic engineer shall ascertain and determine the locations where signals referred to in section 28-101 are required by resorting to field observation, traffic counts and other traffic information as may be pertinent, and his determinations therefrom shall be made in accordance with those traffic engineering and safety standards and instructions set forth in the California Maintenance Manual issued by the Division of Highways of the State Department of Public Works.
(Code 1957, § 6033.2)
Whenever the city traffic engineer installs and maintains an official traffic signal at any intersection, he shall likewise erect and maintain at such intersection, street name signs clearly visible to traffic approaching from all directions, unless such street name signs have previously been placed and are maintained at such intersection.
(Code 1957, § 6033.3)
Whenever the state department of public works determines by resolution and designates a distinctive roadway marking which shall indicate no driving over such marking, the city traffic engineer is authorized to designate by such marking those streets or parts of streets where the volume of traffic or the vertical or other curvature of the roadway renders it hazardous to drive on the left side of such marking or signs and markings. Such marking or signs and markings shall have the same effect as similar markings placed by the state department of public works pursuant to provisions of the vehicle code.
(Code 1957, §§ 6035, 6035.1)
The city traffic engineer is hereby authorized to determine those intersections within any business or residence district at which operators of vehicles shall not make a right turn against a red or stop signal, and shall erect proper signs giving notice of such prohibition.
(Code 1957, § 6039.3)
The city traffic engineer is hereby authorized to mark center lines and lane lines upon the surface of the roadway to indicate the course to be traveled by vehicles and may place signs temporarily designating lanes to be used by traffic moving in a particular direction, regardless of the center line of the highway.
(Code 1957, § 6034)
(a) 
The city traffic engineer is hereby authorized to determine those intersections at which operators of vehicles shall not make a right, left or U-turn, and shall place proper signs at such intersections.
(b) 
The making of such turns may be prohibited between certain hours of any day and permitted at other hours, in which event the same shall be plainly indicated on the signs or they may be removed when such turns are permitted.
(Code 1957, §§ 6039, 6039.1)
The city traffic engineer is authorized to place official traffic-control devices within or adjacent to intersections indicating the course to be traveled by vehicles turning at such intersections.
(Code 1957, § 6038)
The city traffic engineer is authorized to locate and indicate more than one lane of traffic from which operators of vehicles may make right or left turns, and the course to be traveled as so indicated may conform to or be other than as prescribed by law or ordinance.
(Code 1957, § 6038)