You will require this approval if you intend to design a heavy vehicle.
A design must be approved before it can be used to manufacture a heavy vehicle.
The types of businesses that may consider designing heavy vehicles include
manufacturers, operators, transport associations, road transport agencies and
freight customers / shippers.
A heavy vehicle is a vehicle with a gross vehicle mass (GVM) or an
aggregate trailer mass (ATM) of more than 4.5 tonnes.
When you have built your heavy vehicle, you will then need to obtain a
PBS vehicle approval that certifies you have built the vehicle in accordance
with the approved design.
Please consult the responsible agency for more information and to ascertain the level of compliance (if any) that may be required.