It shall be the duty of the officers of the police department, or such officers as are assigned by the chief of police by approval of the council, to enforce all street traffic laws of this city and all of the state vehicle laws applicable to street traffic in the city.
(1999 Code, sec. 70.45)
(a) 
Officers of the police department, or such officers as are assigned by the chief of police upon approval of the council, are authorized to direct all traffic by voice, hand or signal in conformance with traffic laws; provided that, in the event of a fire or other emergency or to expedite traffic or to safeguard pedestrians, officers of the police department may direct traffic as conditions may require notwithstanding the provisions of the traffic laws; and further provided that such officers may be assigned by the chief of police alone in cases of emergency.
(b) 
Officers of the fire department, when at the scene of a fire, may direct or assist the police in directing traffic thereat or in the immediate vicinity.
(1999 Code, sec. 70.46)
(a) 
Whenever he finds it is necessary to the public health, comfort and safety, the chief of police is expected to recommend to the city council areas of the city to be known as “quiet zones” in the vicinity of any hospital, church, school, or public institution and with approval of the city council to mark such area with appropriate signs directing the drivers of vehicles not to sound the horn or other warning device while traveling in the area thus designated.
(b) 
With the approval of the city council, the chief is authorized to:
(1) 
Designate and maintain crosswalks at intersections by appropriate devices, marks, or lines upon the surface of the roadway.
(2) 
Establish safety zones on any of the streets of the city.
(3) 
Mark lanes for traffic on the streets of the city.
(4) 
Determine those intersections at which drivers of vehicles shall not make a right, left, or U-turn and place proper signs at such intersections. The making of such turns may be prohibited between certain hours of any day and be 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 on authority of the council.
(5) 
Place signs, signals, or markings within or adjacent to intersections indicating the course to be traveled by vehicles. Such course to be traveled as so indicated may conform to [or be other than] that prescribed by law or ordinance.
(6) 
Install or cause to be displayed signs, signals, or markings for the direction of traffic near public or private schools, parks, and public buildings.
(7) 
Determine the location of passenger zones and freight loading zones, and place and maintain appropriate signs or markings indicating the same.
(8) 
Designate spaces on the streets of the city for exclusive use as bus zones, and mark the same with appropriate signs or marks.
(9) 
Designate spaces on the streets of the city which shall not be used as spaces for the parking of vehicles, and mark such areas with the appropriate signs or markings.
(10) 
Designate intersections of streets at which drivers operating vehicles approaching the intersection on one or more of the intersecting streets must bring such vehicles to a complete stop before proceeding into such intersection, and install and maintain appropriate signs and markings directing such drivers to stop at such intersections.
(11) 
Designate intersections of streets at which drivers operating vehicles approaching the intersection on one or more of the intersecting streets must reduce the speed of such vehicle to not exceed ten miles per hour upon reaching such intersections and continue at not more than such speed for a distance of 100 feet, and install appropriate signs and markings directing such drivers to reduce the speed of their vehicles.
(12) 
Designate streets and portions of streets on which drivers of vehicles are prohibited from driving except in one direction, and designate the direction in which driving is prohibited and that in which driving is permitted, and install appropriate signs and markings designating such one-way streets.
(13) 
Designate the routes which must be followed by commercial vehicles in using the streets of the city; provided that no such vehicles shall be prohibited from using any street for the purpose of going directly to or from any residential, commercial or industrial establishment abutting on such street.
(14) 
Designate intersections, the crossing of which shall be controlled by red, green and amber lights and arrows as elsewhere herein provided, and determine the type of such lights or traffic-control devices to be installed at each intersection and cause the same to be installed.
(15) 
Determine and allocate parking time limits on streets and portions of streets, and place appropriate signs or markings giving notice thereof.
(16) 
Designate any street as a through street.
(17) 
Determine and designate intersections where particular hazard exists on other than through streets, and determine whether vehicles shall stop at one or more entrances to any such stop intersection; he shall erect a stop sign at every such place where a stop is required upon authority of the council.
(c) 
The chief of police shall have such other powers and duties as are provided for by ordinance.
(d) 
The installation under the direction of the chief of police of any traffic-control device, sign, signal or marking provided for in this chapter shall cause to be effective the instruction to pedestrians or drivers of vehicles transmitted by means of such device, sign, signal or marking.
(1999 Code, sec. 70.47)