Heavy Vehicle (Vehicle Standards) National Regulation (NSW)

A tyre fitted to a heavy vehicle must not have cleats or other gripping devices that could damage road surfaces.

A tyre fitted to the vehicle must have a tread pattern at least 1.5mm deep in all principal grooves on the tyre, other than at tread wear indicators, in a band running continuously—

across at least 75% of the tyre width that normally comes into contact with the road; and

around the whole circumference of the tyre.

A heavy vehicle must not be fitted with a tyre that has been treated by recutting or regrooving the tread rubber, unless the tyre was—

constructed with an extra thickness of rubber designed for recutting or regrooving; and

labelled to indicate the construction.

In this section—

principal grooves, in relation to a tyre, means wide grooves, other than secondary grooves—

usually positioned in the central zone of the tyre tread but that may run across the tyre tread; and

in which tread wear indicators are usually located.

secondary grooves, in relation to a tyre, means shallow grooves in the tyre tread that may disappear during the life of the tyre through wear.

tread wear indicators, in relation to a tyre, means projections within a groove of the tyre that indicate the degree of wear on the tyre’s tread.