It is unlawful for any company, person, or persons to place any railroad cars of any description along the line of any street, in such manner as to prevent the passage of persons or vehicles from one side of the street to the other, on any one square occupied by railroad cars. But in all cases, the company, person, or persons so occupying the street with railroad cars shall leave an opening or space of not less than 20 feet at or near the center of the square or at equal distances from the 2 nearest cross streets. City Code, 1879, art. 40, §6(1st cl.) 1893, art. 41, §6(1st, 2nd cls.) 1927, art. 39, §6(1st, 2nd cls.) 1950, art. 29, §5(1st par.) 1966, art. 20, §5(1st par.) 1976/83, art. 20, §5(1st par.) Rev. Ords. 1858-034 Ord. 48-482 Ord. 99-526