Section 142(2) in The Punjab Motor Vehicles Rules, 1989
(2)The stability of a single decked public service vehicle other than motor cab shall be such that under any conditions of load, at an allowance of 73 kilogrammes for every passenger for which the vehicle is registered if the surface on which the vehicle stands were tilted to either side to an angle of thirty-five degrees from the horizontal the point at which overturning occurs would not be reahced.