A. 
Character and Type Designated: The City Council shall by resolution adopted from time to time determine and designate the character or type of all official traffic lights or signals, subject to Montana Code Annotated Section 61-8-206.
B. 
Placement, Maintenance: Subject to this section and pursuant to such direction and authority as may from time to time be given and furnished by the City Council or the Mayor, the Chief of Police and the City Engineer or Street Superintendent are hereby authorized, and as to those signs and signals required hereunder it shall be their duty, to place and maintain all official traffic signs and signals within the City. All signs required in this article for a particular purpose shall so far as practicable be uniform throughout the City.
C. 
Enforcement; Proper Placement Required: No provisions of this article as to which signs shall be required shall be enforceable against an alleged violator if at the time and place of the alleged violation the signs herein required are not in proper position and sufficiently legible to be seen by an ordinarily observant person.
D. 
Intersections; Left Turns: The Chief of Police and City Engineer or Street Superintendent as further authorized upon direction and authority from the Mayor or from the City Council, by resolution adopted from time to time, to place signs or markers at any and all street intersections in the City where traffic lights are installed and exhibited prohibiting the making of a left-hand turn by any vehicle or conveyance at any such intersection; at any such intersection where a sign or marker is placed prohibiting the making of a left turn by any vehicle or conveyance, it shall be unlawful and a violation of this section to make any such left turn.
(Ord. 537 §§ 1, 5)
A. 
Authority: The Chief of Police or such other person as may be authorized by the Council shall appropriately place, erect or mark with traffic signs, signals or markers on all of the streets, alleys and places requiring them with directional and other signs, signals or markers, in clearly visible places, so as to enable the drivers of motor or other vehicles to comply with this chapter.
B. 
Hazardous Places: The Chief of Police shall also from time to time designate and appropriately mark with stop signs or caution signs all hazardous intersections or other hazardous places in the City. However, before such places or any of them shall be marked, the Chief of Police shall report the proposed designations to City Council and receive the approval of the Council. No person shall operate any motor vehicle, bicycle or other vehicle in violation of any such stop or caution signs.
(Ord. 609 §§ 7, 8)
It shall be unlawful for any driver or operator of any motor vehicle or conveyance or any pedestrian upon or using the streets, avenues or alleys of the City to disobey the instructions of any official traffic sign or signal upon the street placed in accordance with the provisions of this article, unless otherwise directed by a traffic or police officer, subject to the exception granted to drivers of authorized emergency vehicles.
(Ord. 537 § 2)
Whenever traffic at an intersection is alternately directed to stop and to proceed by the use of signals exhibiting the words "stop" and "go," or "caution," or exhibiting colored lights, such terms and lights shall indicate as follows, and no colored lights other than those specified herein shall be used:
A. 
Stop or Red Alone: When the word "stop" or the color red is exhibited, no waiting vehicle facing the signal shall proceed straight ahead or make a left turn until the green or "go" signal is displayed alone; vehicular traffic facing such "stop" or color red shall stop and then may cautiously enter the intersection only to make a right turn, but shall yield the right-of-way to pedestrians lawfully within the crosswalk and to other traffic lawfully using the intersection.
B. 
Go or Green Alone: When the word "go" or the color green is exhibited alone, traffic facing the signal may proceed, either forward or by making a right turn or by making a left turn if a left turn is not prohibited at any such intersection; but any and all such traffic shall yield the right-of-way to pedestrians and vehicles lawfully within a crosswalk or the intersection at the time such signal was exhibited.
C. 
Caution or Amber Alone: When the word "caution" or the color yellow or amber is exhibited following with green, no waiting vehicle facing the signal shall proceed, and every moving vehicle facing the signal shall stop if possible unless at the time the word "caution" or the color yellow or amber is first displayed, the moving vehicle is less than the normal braking distance from the crosswalk, in which event it may proceed; provided, that the same rule shall apply as provided in subsection A of this section to any operator intending to turn his or her motor vehicle to the right at such intersection.
(Art. 537 § 3; amd. Art. 695 § 1)
It shall be unlawful for any person to maliciously remove or injure any public traffic sign, erected upon any public highway, or any inscription on such, to deface the same in writing, or in any other manner; or to remove or disturb any light placed upon a disabled vehicle, or upon any obstruction or defect in the highway.
(R.O. 1947 § 379)
It shall be unlawful for any person to place or maintain, or to display upon or in view of any street, any sign, signal or device which purports to be or is an imitation of, or resembles an official traffic sign or signal, or which attempts to direct the movement of traffic. Every such prohibited sign, signal or device is hereby declared to be a public nuisance, and the Chief of Police is hereby empowered to remove the same, or cause it to be removed, without notice.
(Art. 537 § 4)