W. Va. Code § 24-3-1a – Definitions; telemetry systems required.

(a) As used in this article:
1. (1) "Head end device" means a device located on the lead locomotive of a railroad train designed to receive information from the rear end device. It may also be used to transmit information to the rear end device;
2. (2) "Mainline" means a railroad track extending through railroad yards and between stations which must not be occupied without authority or protection;
3. (3) "Rear end device" means a device located on the rear car of a railroad train designed to transmit information to the head end device and equipped with a rear marker light, red in color, and at least one hundred, but not more than one thousand, candela. It may also be used to receive information from the head end device;
4. (4) "Telemetry system" means a radio transmitter and receiver system between a front end device and a rear end device which indicates through a display at the head end device the following:
  1. (i) Brake pipe pressure at the rear of the train, displayed in increments of one pound per square inch;
  2. (ii) Rear car movement;
  3. (iii) Whether the rear marker light is operating;
  4. (iv) Remaining battery life powering the system;
  5. (v) Any interruption in radio transmission as established by a distance measuring device at the rear end device; and
  6. (vi) The location of the rear of the train as established by a distance measuring device at the rear end device.
(b) It is unlawful to operate a railroad train over one thousand five hundred feet in length on any mainline track within any railroad yard, without an occupied caboose as the rear car of such train unless it is equipped with an operable telemetry system.
(c) No train may depart any crew change point or its point of origin unless the train is equipped with telemetry system as required by this article. Any inoperable system shall be repaired or replaced before leaving the point of origin or at crew change point.
(d) The rear marker light required by this article shall be flashing during the period from one hour before sunset until one hour after sunrise.
(e) Beginning July 1, 1991, all telemetry devices shall be equipped so that an emergency application of the brakes of the train can be initiated at the rear car of the train either by the engineer in the lead or controlling locomotive or by a crew member riding on the rear car.
It is unlawful to institute any disciplinary action or other adverse administrative or employment action against any person who reports a violation or acts to enforce the provisions of this article. Such person's remedies under this chapter shall be in addition to any other remedies that might be available to such person.