Hong Kong Regulations

ROAD TRAFFIC (CONSTRUCTION AND MAINTENANCE OF VEHICLES) REGULATIONS - REGULATION 55

Stability

(1) The stability of a double-decked bus shall be such that when loaded with
weights placed in the correct relative positions to represent the driver and a
full complement of passengers on the upper deck only, if the surface on which
the vehicle stands were tilted to either side to an angle of 28 degrees from
the horizontal, the point at which overturning occurs would not be passed.

(2) The stability of a single-decked bus and light bus shall be such that when
loaded with weights placed in the correct relative positions to represent the
driver and a full complement of passengers, if the surface on which the
vehicle stands were tilted to either side to an angle of 35 degrees from the
horizontal, the point at which overturning occurs would not be passed.

(3) For the purpose of conducting tests of stability the height of any stop
used to prevent a wheel of the bus or light bus from slipping sideways shall
not be greater than two thirds of the distance between the surface upon which
the vehicle stands before it is tilted and that part of the rim of that wheel
which is the nearest to such surface when the vehicle is loaded in accordance
with the requirements of this regulation.

(4) For the purposes of this regulation, 57 kilograms shall be deemed to
represent the weight of one person.