Western Australian Current Regulations Western Australian Current Regulations (1A) In this
regulation —
principal grooves , in relation to a tyre, means
wide grooves, other than secondary grooves —
(a)
usually positioned in the central zone of the tyre tread but that may run
across the tyre tread; and
(b) 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.
(1) A tyre on a motor
vehicle must not have cleats or other gripping devices that could damage road
surfaces.
(2) Except at tread
wear indicators, a tyre fitted to a motor vehicle, trailer or any vehicle in a
combination must have a tread pattern at least 1.5 mm deep in all
principal grooves on the tyre in a band that runs continuously —
(a)
across —
(i)
for a heavy vehicle — at least 75% of the tyre
width that normally comes into contact with the road; or
(ii)
for a light vehicle — the tyre width that
normally comes into contact with the road;
and
(b)
around the whole circumference of the tyre.
(3) A motor vehicle,
trailer or any vehicle in a combination must not be fitted with a tyre that
has been treated by recutting or regrooving the tread rubber, unless the tyre
was —
(a)
constructed with an extra thickness of rubber designed for recutting or
regrooving; and
(b)
labelled to indicate the construction.
[Regulation 270 amended: SL 2024/107
r. 4.]