4. When operating flasher-equipped straight truck utility vehicles that have permanently mounted equipment that extends up to 9 feet beyond the front bumper, provided:
a. Such equipment, when in the travel position, is supported in such a manner that it has a minimum of 80 inches clearance above the roadway;
b. Such equipment is illuminated on the forwardmost sides with high visibility reflective tape;
c. The respective daytime and nighttime requirements for operation are otherwise met;
d. Nighttime emergency or required maintenance operation of such utility vehicles with overall lengths in excess of 50 feet are led by a company-provided flasher-equipped escort vehicle; and
e. Trailers are not pulled by utility vehicles over 50 feet in length.
A flasher-equipped escort vehicle is defined as an automobile or truck that closely accompanies an over dimensional vehicle or load carried thereon to alert approaching traffic of that vehicle or load. Such escort vehicles shall be equipped with a working warning light device, as defined in this subsection, except that such device shall be located on top of the escort vehicle. Warning light devices required in this subsection shall be consistent with size, color, type, intensity, and mounting requirements developed by the Department of Transportation.