PBS vehicle standards

Vehicles are assessed under the Performance-Based Standards (PBS) scheme according to 16 minimum vehicle performance standards to ensure they are stable on the road and can turn and stop safely. Additionally, there are four infrastructure protection standards.

Below is a short description of the current standards illustrated by a diagram. For more information please refer to the PBS Standards and Vehicle Assessment Rules.

Longitudinal performance (low speed)





Ability to commence forward motion on specified grade

 Startability Diagram 




Ability to maintain forward motion on specified grade; and achieve a minimum speed on 1% grade

 Gradeability Diagram
Acceleration capability




Ability to accelerate either from rest or to increase speed on a road

 Acceleration Capability Diagram 
Tracking ability on a straight path




The total swept width while travelling on a straight path

Tracking Ability on a Straight Path Diagram

 Directional performance (low speed)

Low speed swept path




The maximum width of the swept path in a prescribed 90° low speed turn

Low Speed Swept Path Diagram 
Frontal swing




Maximum lateral outswing of the front outside corner of the prime mover and trailer

Frontal Swing Diagram
Tail swing




Maximum lateral out-swing of the outside rear corner of the truck or trailer as the turn commences

Tail Swing Diagram
Steer tyre friction demand




Maximum steer tyre friction in a prescribed low speed turn

Steer Tyre Friction Demand Diagram
Static rollover threshold




The steady-state level of lateral acceleration that a vehicle can sustain during turning without rolling over

Static Rollover Threshold Diagram
Rearward amplification




Measures the ‘whip crack’ effect of a lane change manoeuvre

Rearward Amplification Diagram
High speed transient offtracking




The lateral distance that the last-axle on the rear trailer tracks outside the path of the steer axle in a sudden evasive manoeuvre

High Speed Transient Offtracking Diagram
Yaw damping coefficient




The rate of decay of the “sway” from the rearmost trailer after a single pulse steering movement.

Yaw Damping Coefficient Diagram

 Infrastructure protection standards

Pavement vertical loading




Degree to which vertical forces are applied to the pavement

Pavement Vertical Loading Diagram

Pavement horizontal loading




Degree to which horizontal forces are applied to the pavement

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Tyre contact area




Degree to which tyre contact pressure is distributed over the pavement

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Bridge loading




The maximum effect on a bridge measured relative to a reference vehicle

Bridge Loading Diagram