Section 150(2) in The Punjab Motor Vehicles Rules, 1989
(2)In the case of a double-decked vehicle, -(a)the risers of all steps leading from the lower to the upper deck shall be closed and no unguarded aperture shall be left at the top landing board;(b)all steps leading from the lower to upper deck shall be fitted with non-slip treads;(c)the horizontal distance from the nearest point of the riser of the top step to the vertical line passing through the nearest point of the seat opposite to the top tread of the staircase excluding any grab rail which does not project more than 75 millimetres from back of the seat, shall not be less than 660 millimetres; and(d)the outer stringer of an outside staircase shall be so constructed or a band shall be so placed, as to act as a screen to persons ascending or descending and the height of the outer guard rail shall not be less than one metre above the front of the tread of each step.
