Every motor vehicle shall be so constructed or equipped that the exhaust gases from the engine are discharged neither downward nor to the left side of the vehicle and shall be so fitted as to allow the gases to escape to the right side or rear of the vehicle:
Provided that in the case of tankers carrying explosives and inflammable goods, the fitment of exhaust pipe shall be according to the specification of the Inspector of Explosives:
[Provided further that in the vehicles where the exhaust gases are discharged to the right of the vehicle, slight downward angle shall be permitted, provided the exhaust gases do not kick up any dust when the vehicle is stationary and engine running and in any case the angle of the pipe to the horizontal should not be more than 30degrees:
Provided also that where the exhaust gases are discharged to the left of the vehicle the inclination of exhaust pipe should not cross 30 degrees in downward and 30 degrees in left direction against the vertical plane which includes the vehicle centre line,provided the exhaust gases do not take up any dust when the vehicle is stationary and engine running:
[Provided further that in the case of agricultural tractors, vertical or horizontal] exhaust pipe may be provided and outlet of this pipe should be so directed that the driver of the tractor is not exposed to exhaust gases by locating the outlet over or to the side of head-level of the driver as per Indian Standards IS: 12239 (Part1)1988:]
[Provided also that in the case of construction equipment vehicle [and combine harvester] vertical exhaust pipe may be fitted and outlet of this pipe shall be so directed that the driver of the vehicle is not exposed to exhaust gases.]