Semi-trailers, B-doubles and other combinations fitted with quad-axle groups can carry heavy loads more safely on a defined road network.
'Blueprint' designs for quad-axle semi-trailers and B-doubles have been pre-approved using Performance-Based Standards (PBS) and made available to the heavy vehicle industry. Operators can use these 'blueprints' to apply for access on a PBS networks.
A new National Class 2 Heavy Vehicle B-double Notice commenced on 1 February 2019.
A B-double permit is required for travel on a road outside of the approved B-double network.