(1) If at any time it appearsto ahighway authority that any highway in its charge or any portion thereof is or has been rendered unsafe for vehiCuIaT or pedestrain trafiic by reason of damage or otherwise, it may, subject to such rules as may be prescribed in this behalf, either close the highway or the portion of it to all traflic or to any class of traffic, or regulate the number and speed of vehicles using the highway.
40. Where the highway authority is satisfied that the surface of any highway, 'or a portion thereof. or any bridge; culvert or causeway built on or across any highway, is not designed to carry Vehicles of which the laden weight exceeds acertain limit it may subject to such rules as may be prescribed in this behalf, prohibit or restrict the plying of such vehicles on or over such highway or such part of the highway or such bridge, culvert or causeway.