Section 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.