Section 239(1) in The West Bengal Motor Vehicles Rules, 1989
(1)Every public service vehicle other than a motor cab shall be so constructed that -(i)in the case of a single-decked vehicle with an enclosed body, -(a)the height of the body sides from the floor or the height to the stills of the windows, as the case may be, shall not be less than 71 centimetres;(b)if the height of the sides of the body or of the sills of the windows, as the case may be, above the highest part of any seat is less than 46 centimetres, provision shall be made by means of guard rails or otherwise. to prevent the arms of seated passengers being thrust through and being injured by passing vehicle, or the extent to which the side windows or venetians can be lowered in such a manner that when lowered their top-edge is not less than 46 centimetres above the highest part of any seat;(ii)in the case of a single-decked vehicle with open sides, guard rails shall be provided along the right hand side of the vehicle to prevent any person other than the driver from mounting or alighting from the vehicle on that side;(iii)in the case of single-decked vehicle, the rear windows shall be covered from outside with close-spaced strong wire nets and the rear shall be fixed with slanted planks rigidly to ensure blocking of foot-hold on the rear outer body of the vehicle:(iv)in the case of a double-decked vehicle with an uncovered top-deck, the top-deck shall be provided with side and end rails, the top of which shall be at least 91 centimetres above the deck boards or battens at the sides and 46 centimetres above the highest part of any seat, and that top of the front and back rails shall be at least 99 centimetres above the deck boards or battens and shall follow the camber of the deck.
