It is unlawful for any person to park or permit to stand any commercial motor vehicle having a gross weight of six thousand pounds or more, by its manufacturer's rating, or any semitrailer motor vehicle or any trailer on any of the following streets or alleys or portions thereof in the city:

    A.    On any street with curbs where the width thereof is forty-six feet or less from back of curb to back of curb;

    B.    On any street without curbs where the width of the paved or traveled portion of such street is forty-six feet or less;

    C.    On any alley. (Prior code § 15-86)