7. A school bus shall be manufactured in such a manner that
(1) it is not more than 12.20 m long, measured from bumper to bumper;
(2) the length of its rear cantilever is less than one-third of its total length;
(3) its turning radius is not more than 13 m where its wheelbase is 6,700 mm or less, and not more than 13.5 m where its wheelbase is greater than 6,700 mm;
(4) where it is fitted with side rails, they are manufactured in one piece between the front hanger of the front spring and the rear hanger of the rear spring;
(5) the load exerted on each axle corresponds to at least 30% of both the total loaded mass and the net mass;
(6) if its suspension is equipped with leaf springs, it has a device preventing misalignment of the front axle in the case of breakage; and
(7) its exhaust pipe and muffler are attached to the chassis without passing through the passenger compartment.