Obeying devices -- Effect of improper position, illegibility, or absence -- Presumption of lawful placement and compliance with chapter

(1) (a) Except as otherwise directed by a peace officer or other authorized personnel under Section 41-6a-209 and except as provided under Section 41-6a-212 for authorized emergency vehicles, the operator of a vehicle shall obey the instructions of any traffic-control device placed or held in accordance with this chapter. (b) A violation of Subsection (1)(a) is an infraction. (2) (a) Any provision of this chapter, for which a traffic-control device is required, may not be enforced if at the time and place of the alleged violation the traffic-control device is not in proper position and sufficiently legible to be seen by an ordinarily observant person. (b) The provisions of this chapter are effective independently of the placement of a traffic-control device unless the provision requires the placement of a traffic-control device prior to its enforcement. (3) A traffic-control device placed or held in a position approximately conforming to the requirements of this chapter is presumed to have been placed or held by the official act or direction of a highway authority or other lawful authority, unless the contrary is established by competent evidence. (4) A traffic-control device placed or held under this chapter and purporting to conform to the lawful requirements of the device is presumed to comply with the requirements of this chapter, unless the contrary is established by competent evidence.