Sec. 489(58). Signal devices.
(a) Any motor vehicle which is so constructed or carries a
load in such manner as to prevent the hand and arm signal described
in this section from being visible both to the front and
rear of such vehicle shall be equipped with a mechanical or electrical
signal device which meets the requirements of this section
and is of a type approved by the Director of the Division of Motor
Vehicles.
(b) Every device intended to give a signal of intention to turn
or stop a vehicle shall give a signal plainly visible at all times
from a distance of at least one hundred feet to the rear of the
vehicle upon which it is used.
(c) The Director of the Division of Motor Vehicles is authorized
to adopt and enforce rules and regulations not inconsistent
with this section governing the construction, location, and
operation of signal devices and the color of lights which may be
used in any such electric devices. The Director is authorized to
accept a certificate of the United States bureau of standards of
some other recognized testing laboratory having an arrangement
with the said bureau by which appeal may be made to it in case
of dispute as to the findings of such other laboratory, which certificate
certifies that a signal device is of a type which has been
found to meet the regulations of the Director with reference
thereto.
(d) It shall be unlawful for any person to sell or offer for
sale, either separately or as a part of the equipment of a vehicle,
or to use upon a vehicle on a highway any signal device intended
to give notice of intention to turn or stop the vehicle upon which
it is used unless meeting the requirements of this section and of
a type first approved by the Director.
