WVC 17 C- 8 - 9
§17C-8-9. Signals to be given by hand and arm or signal device.
Any stop or turn signal when required herein shall be given
either by means of the hand and arm or by a signal lamp or lamps
or mechanical signal device, but when a vehicle is so constructed
or loaded that hand-and-arm signal would not be visible both to
the front and rear of such vehicle then said signals must be
given by such a lamp or lamps or signal device.