It shall be unlawful for any person intentionally or carelessly to throw, cast, put into, drop or leave in any street, gutter, sidewalk or public place any stones, gravel, sand, coal, dirt, manure, garbage, leaves, lawn or hedge clippings or rubbish of any kind, or any other substances which shall render such highway unsafe or unsightly, or shall interfere with travel thereon. (1960 Code § 12-7)