Section 78-A. Electric or battery-powered markers

1. Any railroad using a
  passenger, mail, work, or wreck train shall equip the last car  of  each
  such  train  with  electric  markers  of  sufficient  candle power to be
  visible for a distance of  three  thousand  feet  under  normal  weather
  conditions.  Battery-powered, flashing-type, or constant burning markers
  shall be deemed sufficient compliance with the foregoing requirement.
    2. If, in any particular case, exemption from any of the  requirements
  herein  is  deemed necessary by the railroad concerned, the commissioner
  of transportation may grant the application of such railroad,  for  such
  exemption  when  accompanied  by a petition setting forth the conditions
  existing and the reason why such exemption is asked.   Any exemption  so
  granted shall be limited to the particular case covered by the petition.