ARTICLE 4 - TRAFFIC-CONTROL DEVICES
31-5-401.� Duty of local authorities to place and maintain.
Local authorities in their respective jurisdictions shall place and maintain such traffic-control devices upon highways under their jurisdiction as they deem necessary to indicate and to carry out the provisions of this act or local traffic ordinances or to regulate, warn or guide traffic. All traffic-control devices hereafter erected shall conform to the state manual and specifications.
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 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.
31-5-403.� Signal legend generally.
(a)� Whenever traffic is controlled by traffic-control signals exhibiting different colored lights, or colored lighted arrows, successively one (1) at a time or in combination, only the colors green, red and yellow shall be used, except for special pedestrian signals carrying a symbol or word legend, and the lights shall indicate and apply to drivers of vehicles and pedestrians as follows:
(i)� Green indication:
(A)� Vehicular traffic facing a circular green signal may proceed straight through or turn right or left unless a sign prohibits either turn. But vehicular traffic, including vehicles turning right or left, shall yield the right-of-way to other vehicles and to pedestrians lawfully within the intersection or an adjacent crosswalk at the time the signal is exhibited;
(B)� Vehicular traffic facing a green arrow signal, shown alone or in combination with another indication, may cautiously enter the intersection only to make the movement indicated by the arrow, or such other movement as is permitted by other indicators shown at the same time.� The vehicular traffic shall yield the right-of-way to pedestrians lawfully within an adjacent crosswalk and to other traffic lawfully using the intersection;
(C)� Unless otherwise directed by a pedestrian-control signal, as provided by W.S. 31-5-404, pedestrians facing any green signal, except when the sole green signal is a turn arrow, may proceed across the roadway within any marked or unmarked crosswalk.
(ii)� Steady yellow indication:
(A)� Vehicular traffic facing a steady circular yellow or yellow arrow signal is thereby warned that the related green movement is being terminated or that a red indication will be exhibited immediately thereafter;
(B)� Pedestrians facing a steady circular yellow or yellow arrow signal, unless otherwise directed by a pedestrian-control signal as provided by W.S. 31-5-404, are thereby advised that there is insufficient time to cross the roadway before a red indication is shown and no pedestrian shall then start to cross the roadway.
(iii)� Steady red indication:
(A)� Vehicular traffic facing a steady circular red signal alone shall stop at a clearly marked stop line, but if none, before entering the crosswalk on the near side of the intersection or, if none, then before entering the intersection and shall remain standing until an indication to proceed is shown except as provided in subparagraph (C) of this paragraph;
(B)� Vehicular traffic facing a steady red arrow signal shall not enter the intersection to make the movement indicated by the arrow and, unless entering the intersection to make a movement permitted by another signal, shall stop at a clearly marked stop line, but if none, before entering the crosswalk on the near side of the intersection, or if none, then before entering the intersection and shall remain standing until an indication permitting the movement indicated by the red arrow is shown except as provided by subparagraph (C) of this paragraph;
(C)� Except when a sign is in place prohibiting a turn, vehicular traffic facing any steady red signal may cautiously enter the intersection to turn right, or to turn left from a one-way street into a one-way street after stopping as required by subparagraphs (A) and (B) of this paragraph. The vehicular traffic shall yield the right-of-way to pedestrians lawfully within an adjacent crosswalk and to other traffic lawfully using the intersection;
(D)� Unless otherwise directed by a pedestrian-control signal as provided by W.S. 31-5-404, pedestrians facing a steady circular red or red arrow signal alone shall not enter the roadway.
(b)� If an official traffic-control signal is erected and maintained at a place other than an intersection, this section is applicable except as to those provisions which by their nature can have no application. Any stop required shall be made at a sign or marking on the pavement indicating where the stop shall be made, but in the absence of any sign or marking the stop shall be made at the signal.
31-5-404.� Pedestrian-control signals.
(a)� Whenever special pedestrian-control signals exhibiting the symbols or words "Walk" or "Don't Walk" are in place the signals shall indicate as follows:
(i)� Flashing or steady walk: �Any pedestrian facing the signal may proceed across the roadway in the direction of the signal and every driver of a vehicle shall yield the right-of-way to him;
(ii)� Flashing or steady don't walk: �No pedestrian shall start to cross the roadway in the direction of the signal, but any pedestrian who has partially completed his crossing on the walk signal shall proceed to a sidewalk or safety island while the don't walk signal is showing.
31-5-405.� Flashing signals.
(a)� Whenever an illuminated flashing red or yellow signal is used with or in a traffic sign or signal it shall require obedience by vehicular traffic as follows:
(i)� Flashing Red (Stop Signal): �When a red lens is illuminated with rapid intermittent flashes, drivers of vehicles shall stop at a clearly marked stop line, but if none, before entering the crosswalk on the near side of the intersection, or if none, then at the point nearest the intersecting roadway where the driver has a view of approaching traffic on the intersecting roadway before entering it, and the right to proceed is subject to the rules applicable after making a stop at a stop sign;
(ii)� Flashing Yellow (Caution Signal): �When a yellow lens is illuminated with rapid intermittent flashes, drivers of vehicles may proceed through the intersection or past the signal only with caution.
(b)� This section shall not apply at railroad grade crossings. Conduct of drivers of vehicles approaching railroad grade crossings shall be governed by the rules provided by W.S. 31-5-510.
31-5-406.� Display of unauthorized signs; advertising on traffic signs.
(a)� No person shall place, maintain or display upon or in view of any highway any unauthorized sign, signal, marking or device which purports to be or is an imitation of or resembles an official traffic-control device or railroad sign or signal, or which attempts to direct the movement of traffic, or which hides from view or interferes with the effectiveness of any official traffic-control device or any railroad sign or signal.
(b)� No person shall place or maintain nor shall any public authority permit upon any highway any official traffic-control device bearing thereon any commercial advertising except for business signs included as a part of official motorist service panels or roadside information panels approved by the highway department.
(c)� This section does not prohibit the erection upon private property adjacent to highways of signs giving useful directional information and of a type that cannot be mistaken for official signs.
(d)� Every prohibited sign, signal or marking is a public nuisance and the authority having jurisdiction over the highway may remove the same or cause it to be removed without notice.