The Australian version of heavy truck Performance Based Standards (PBS) scheme was instigated in 1997/98 by the then National Road Transport Commission (NRTC). The scheme allowed for longer and heavier vehicles that performed to now some 16 enhanced engineering standards. State permits can still be issued even though the PBS framework has been in place since 2006 after being agreed by ministers.
The scheme was formally handed over to the new NHVR in 2013. The performance of the Australian PBS truck populations was examined through three studies that spanned the 10 year period from 2013 to 2023. The productivity benefits that are directly safety related are examined in this paper.
Source: National Heavy Vehicle Regulator
Figure 1 shows the growth in the PBS population – since 2016 there has been a factor of five increase. This growth over this period was stunning.
The growth in take-up of the PBS scheme, since its inception, was initially viewed as a ‘physical’ productivity initiative. However, directly linked to these ‘physical productivity’ benefits was large savings in freight kilometres travelled.
Statistically savings in freight kilometres travelled can be translated into both crash, serious injury and fatality savings.
As an aside insurers do take into account, when setting insurance premia, the total kilometres that truck fleets actually travel. So, kilometres saved will have a statistical link to truck crash savings. Therefore, to get a snapshot on the safety performance of Australia’s PBS fleet, the first major PBS review was commissioned 2014, followed two subsequent reports in 2017 and 2021.
At an initial level a comparison of the crash rates of PBS versus conventional heavy vehicles is presented in Table 1. It can be seen that for the two metrics examined, there are significantly lower crash rates for the PBS truck population.
Table 1. Major Crash Rates Conventional vs PBS Vehicles
| Configuration | Registration Class | Major Crash Rates | |
| Per 100 million kms | Per 10K Vehicles | ||
| Light Rigid | Conventional | 8.0 | 24.0 |
| Medium Rigids | Conventional | 14.8 | 24.4 |
| Heavy Rigids | Conventional | 14.7 | 33.1 |
| Heavy Rigids (Trailer) | Conventional | 16.7 | 119.7 |
| Heavy Rigids (Trailer) PBS | PBS | 8.8 | 98.7 |
| Semi-Trailer | Conventional | 19.3 | 148.9 |
| Semi-Trailer (PBS) 20m Trailer Quad axle | PBS | 2.8 | 98.6 |
| B-Double | Conventional | 9.6 | 151.5 |
| Super B-Double (PBS) | PBS | 8.5 | 122.4 |
| Enhanced B-Double (PBS) | PBS | 3.7 | 76.4 |
| B-Triple | PBS/Permit | 3.7 | 59.4 |
| A-Double | PBS | 11.4 | 149.1 |
| Type I (Double Road Train) | Conventional | 23.03 | 286.8 |
| Type II (Triple Road Train) | Conventional | 23.86 | 296.4 |
| Road Train (Quad Trailer)1 | Conventional | 61.98 | 787.8 |
| Road Train (AAB, BAB Quad (trailer) | PBS | 5.4 | 119.4 |
| Road Train (Quin Trailer) | Permit | na | na |
Sources: Derived from Austroads 2014, NTC 2017, NHVR 2021
The kilometres saved, which are central to estimating crash reduction benefits, is presented in Table 2 where there are significant vehicle crash reductions gained through the use of High Productivity Vehicles approved through the PBS scheme.
Table 2 which, from a fatality savings perspective, is an exceptionally important safety benefit of the PBS scheme. It shows that as the PBS fleet numbers increase, the kilometres saved will generate statistical safety benefits.
Table 2. Forecast fatality savings through PBS kilometres saved
| Year | Fatals rate / Bill kms | Bill Kms saved | Fatals Saved |
| 2024 | 7.5 | 1.442 | 10.81 |
| 2023 | 7.5 | 1.12 | 8.4 |
| 2022 | 7.6 | 0.957 | 7.27 |
| 2021 | 7.6 | 0.81 | 6.15 |
| 2020 | 7.6 | 0.69 | 5.25 |
| 2019 | 9 | 0.456 | 4.1 |
| 2018 | 7.4 | 0.376 | 2.78 |
| 2017 | 9.3 | 0.296 | 2.76 |
| 2016 | 9 | 0.217 | 1.95 |
| 2015 | 9.6 | 0.167 | 1.6 |
| 2014 | 9.9 | 0.118 | 1.16 |
| 2013 | 9 | 0.068 | 0.61 |
| Total | na | 6.717 | 52.84 |
Source: Hassall et al, (2023), NHVR (2021) and statistical factors from BITRE data
The fatality rates, as published by BITRE up to 2021, reflect the number of fatalities per billion truck kilometres travelled, as a corollary savings in billions of kilometres can statistically reflect a calculable level of fatalities savings.
The calculations for estimating kilometres saved have been published in Austroads in 2014, NTC in 2018, NHVR in 2021 and Hassall et al in 2023. In brief, the more PBS vehicles that become operational, the greater are the kilometre savings and this leads to potential fatality savings. Basically, less kilometres equals less on road risk. This is a basic insurance risk metric. The fatality savings may well be higher as the forecast improvement in the fatality rates per billion kilometres may not be as low as presented.
Why is PBS delivering safety outcomes?
There are potentially four areas that contribute to the safety benefits associated with PBS truck use.
Engineering standards
Firstly the 16 ‘tighter’ engineering standards reflects better vehicle handling. These standards can be found on the regulator’s website.
Constrained road access – appropriate roads for appropriate PBS trucks
The various PBS truck configurations are constrained to quite specific road networks. The defined road levels can be found on the regulator’s website.
Experienced Drivers
As much as it is anecdotal, arising from surveys (Austroads, 2014), generally more experienced drivers were more often used to drive the company’s PBS vehicles. Why should this be so? PBS vehicles are a more costly investment than a conventional truck. As an example, a quad road train rollover may well incur a $1 million dollar crash claim.
The PBS fleet is far more productive than a conventional truck fleet
Possibly the most significant contribution to safety is the kilometres saved through the use of PBS vehicles, as the vehicles’ extra cargo capacity leads to lower kilometres travelled for the same tasks being undertaken by a conventional vehicle fleet. Table 2 above reflects these kilometre savings through to 2033.
Dispelling Perceptions
Big trucks are bad. This is the perception of the community, the press and unfortunately many academics. However, the high productivity vehicles, approved under the Performance Based Standards scheme, turns this perception on its head. Under PBS, bigger is probably better. Almost after 30 years this fact has only slowly been accepted. Perceptions are not fact – PBS proves this.