It shall hereafter be unlawful for any person or persons to move or operate heavy equipment across any curb, gutter, bridge, culvert, sidewalk, crosswalk or crossing on any unpaved street without first having protected such curb, gutter, bridge, culvert, sidewalks, crosswalk or crossing, with heavy plank sufficient in strength to warrant against the breaking or damaging of such curb, gutter, bridge, culvert, sidewalk, crosswalk or crossing. Hereafter, it shall be unlawful to run, drive, move, operate or convey over or across, any paved street a vehicle, machine or implement, with sharp discs or sharp wheels, that bear upon said pavement; with wheels having cuttings edges; with wheels having lugs, or any protruding parts, or bolts thereon that extend beyond a plain tire so as to cut, mark, mar, indent or otherwise injure or damage any pavement, gutter or curb; provided, where heavy vehicles, structures, and machines move along paved or unpaved streets, the City Council is hereby authorized and empowered to choose the route over which the moving of such vehicles, structures or machines will be permitted and allowed; provided, school buses and emergency vehicles shall be permitted to use metal or metal-type studs all year; it shall be permissible to use farm machinery with tires having protuberances which will not injure the streets; and it shall be permissible to use tire chains of reasonable proportions upon any vehicle when required for safety because of snow, ice or other condition tending to cause a vehicle to slide or skid.