All fines or forfeitures collected upon conviction or upon the forfeiture of bail of any person charged with a violation of any of the provisions of this traffic code shall be paid into the City Treasury and deposited into a special fund to be known as the Street Fund, which is created and which shall be used exclusively in the construction, maintenance and repair of public streets, bridges and street structures, or for the installation and maintenance of traffic-control devices thereon.
('71 Code, § 70.33)