Whenever any tracks are laid upon trestle or pile formations along the streets of the city, the space between the tracks, for the entire width, shall be filled in, in the same manner as provided for in § 20-224, or the whole distance between the rails and tracks shall be entirely planked over with two-by-12 plank, securely spiked down and made safe for traffic over them, and the sides sloped off for a distance of six feet by filling or planking.
(1964 Code, § 31-22)