W. Va. Code § 17C-12-8: Special lighting equipment on school buses.

(a) The Commissioner of Motor Vehicles is authorized to adopt standards and specifications applicable to lighting equipment on and special warning devices to be carried by school buses consistent with the provisions of this chapter, but supplemental thereto, and except that such standards and specifications may designate and permit the use of flashing warning signal lights on school buses for the purpose of indicating when children are boarding or alighting from any said bus. Such standards and specifications shall correlate with and, so far as possible, conform to the specifications then current as approved by the Society of Automotive Engineers.

(b) It shall be unlawful to operate any flashing warning signal light on any school bus except when any said school bus is stopped or is slowing down to stop on any street or highway for the purpose of permitting school children to board or alight from said school bus.