Brake testing using roller brake testers is conducted to ensure that brakes are properly maintained. The pass criteria for a roller brake test is currently a minimum of 4kN/wheel and no more than a 30% difference in brake force between wheels on an axle.

There are concerns that:​

1. the minimum brake force requirement is inadequate for heavily laden vehicles and too stringent for lightly laden vehicles;​
2. the brake balance requirement across axles is unecessary;​
3. the in-service roller brake tester standards do not have any relationship with the braking system standards of Australian Design Rules (ADR’s) with which vehicles were originally designed to comply.

As a consequence of the above concerns and following a review of brake test standards in use in other countries a series of tests was conducted with the aim of:​

1. determining the relationship between the brake forces measured by the VIT and actual braking performance of a heavy vehicle;​
2. determining the relationship between brake force balance as measured by the VIT and actual truck behaviour during braking;​
3. establishing a relationship between roller brake testing and standards compliance testing.

A strong relationship has been found to exist between the weight on a wheel and the brake force that wheel is capable of generating. On the basis of this relationship it is proposed to adopt a new minimum braking requirement expressed in kN/tonne.

A relationship between brake imbalance and vehicle performance was also established.

The practicality of the proposed brake test standards has been assessed by evaluating it against the roller brake test data obtained in two statewide heavy vehicle roadworthiness surveys.