124Certain vehicles used for collection or exhibition purposes

124 Certain vehicles used for collection or exhibition purposes This Part does not apply to a vehicle built before 1946 that is used mainly for exhibition purposes. Note This Part sets out the braking system requirements for vehicles to ensure that they can be reliably slowed or stopped even if a part of a braking system fails, and to ensure that a vehicle can be prevented from rolling away when parked. The Part also includes special requirements for braking systems on B-doubles and road trains to ensure that the braking systems on the component vehicles are compatible. The special requirements do not apply to a road train that is 19 metres long or less.