R920-8-8. Exceptions

  (1) When multiple vehicles are engaged in highway construction and maintenance operations, and are concentrated within a small area in a work zone, it is acceptable for those vehicles within the perimeter of vehicles to reduce the intensity or turn off the flashing amber lighting systems and/or supplemental flashing lighting systems to minimize the distractions to motorists and other workers in the work zone.

  (2) Delivery vehicles are not required to have a flashing amber lighting system, but must use vehicle hazard lights when entering or exiting a work zone.