31-5-402. Obedience to devices; exceptions. (a) The driver of any vehicle shall obey the instructions of any official traffic-control device applicable thereto placed or held in accordance with this act unless otherwise directed by a police officer, subject to the exceptions granted the driver of an authorized emergency vehicle in this act. (b) No provision of this act for which official traffic-control devices are required shall be enforced against an alleged violator if at the time and place of the alleged violation an official device is not in proper position and sufficiently legible to be seen by an ordinarily observant person. Whenever a particular section does not state that signs are required, the section is effective even though no signs are erected or in place. (c) Whenever official traffic-control devices are placed or held in position approximately conforming to the requirements of this act, the devices are presumed to have been so placed or held by the official act or direction of lawful authority unless the contrary is established by competent evidence. (d) Any official traffic-control device placed or held pursuant to the provisions of this act and purporting to direction of lawful authority unless the contrary is established by competent evidence. (d) Any official traffic-control device placed or held pursuant to the provisions of this act and purporting to conform to the lawful requirements pertaining to the devices is presumed to comply with the requirements of this act unless the contrary is established by competent evidence.
Wyoming Legal Code