(1) Every motor vehicle when operated upon a highway shall be equipped with a horn in good working order and capable of emitting sound audible under normal conditions from a distance of not less than 200 feet.
(2) No horn or other warning device shall emit an unreasonably loud or harsh sound or a whistle.
(3) The driver of a motor vehicle shall, when reasonably necessary to ensure safe operation, give audible warning with his or her horn, but shall not otherwise use such horn when upon a highway.
(4) No vehicle shall be equipped with, nor shall any person use upon a vehicle, any siren, whistle, or bell, except as otherwise permitted in this section.
(5) It is permissible but not required that any vehicle be equipped with a theft alarm signal device which is so arranged that it cannot be used by the driver as an ordinary warning signal.
(6) Every authorized emergency vehicle shall be equipped with a siren, whistle, or bell capable of emitting sound audible under normal conditions from a distance of not less than 500 feet and of a type approved by the department, but such siren, whistle, or bell shall not be used except when the vehicle is operated in response to an emergency call or in the immediate pursuit of an actual or suspected violator of the law, in which event the driver of the vehicle shall sound the siren, whistle, or bell when reasonably necessary to warn pedestrians and other drivers of the approach thereof.
(7) Notwithstanding the other provisions of this section, a trolley may be equipped with a bell, and the bell is not required to be used only as a warning device. As used in this subsection, the term “trolley” includes any bus which resembles a streetcar, which is powered by overhead electric wires or is self-propelled, and which is used primarily as a public conveyance.
(8) A violation of this section is a noncriminal traffic infraction, punishable as a nonmoving violation as provided in chapter 318.