With this in mind, both farmers and motorists are urged to be vigilant in several key situations. Passing: Since 2014, Wisconsin law has prohibited passing farm machinery in no-passing zones, no matter the speed. Most farm equipment has flashing amber or yellow lights; the light on the turn side keeps flashing while the other remains steady. Most farm equipment has flashing amber or yellow lights; the light on the turn side keeps flashing while the other remains steady. Controlled Intersections: Farm equipment requires more braking distance due to weight.