Section 157 in The Bihar Motor Vehicles Rules, 1992
157. Head room.
- Every public service vehicle other than a motor cab shall have the following internal height or head room measured along the centre of the vehicle from the top of the floor boards or battens to the underside of the root supports:-(i) in the case of single decked vehicle and lower deck of double decked vehicle, not less than 1.75 meters and not more than 2 meters, (ii) in the case of upper deck of a double decked vehicle not more than 1.7 meters, (iii) in the case of a vehicle having capacity to carry not more than 15 passengers, not less than 1.30 meters.
