The sounding of any horn or signal device on any automobile, motorcycle, bus, streetcar or other vehicle while not in motion, except as a danger signal if another vehicle is approaching apparently out of control or to give warning of intent to get under motion, or if in motion, only as a danger signal after or as brakes are being applied and deceleration of the vehicle is intended; the creation by means of any such signal device of any unreasonably loud or harsh sound; and the sounding of such device for an unnecessary and unreasonable period of time are unlawful.
(Prior Code, § 17-4) Penalty, see § 10.99