AB91-SA1,1,147
347.25
(5) Notwithstanding s. 347.26 (11), whenever flashing warning lamps
8on an authorized emergency vehicle are designed and being used to exhibit a
9directional arrow at the scene of an emergency, all such lamps exhibiting the
10directional arrow shall be flashing simultaneously. If the use of flashing warning
11lamps to exhibit a directional arrow would likely direct approaching traffic into a
12lane of traffic moving in the opposite direction, only the flashing warning lamps that
13exhibit the horizontal bar of a directional arrow may be used and such lamps shall
14be flashing simultaneously.".