70.052: FLASHING SIGNALS:
   A.   Requirements: Whenever an illuminated flashing red or yellow signal is used in a traffic sign or signal, it shall require obedience by vehicular traffic as follows:
      1.   Flashing Red (Stop Signal): When a red lens is illuminated with rapid intermittent flashes, drivers of vehicles shall stop before entering the nearest crosswalk at an intersection or at a limit line when marked, or if none, then before entering the intersection; and the right to proceed shall be subject to the rules applicable after making a stop at a stop sign.
      2.   Flashing Yellow (Caution Signal): When a yellow lens is illuminated with rapid intermittent flashes, drivers of vehicles may proceed through the intersection or past such signal only with caution.
   B.   Exception: This section shall not apply at railroad grade crossings. (2001 Code § 70.052)