The Commissioners shall from Time to Time place such Fences and Posts on the Side of the Footways' of the Streets under their Management as may be needed for the Protection of Passengers on such Footways, and they may place Posts in the Carriageways of such Streets, so as to make the crossing thereof less dangerous for Foot Passengers ; and they shall from Time to Time repair any such Fences or Posts, or remove the same, or any Obstructions to any such Carriageway or Footway, as they think fit.