When the idea of PBS was first given serious thought in Australia more than a decade ago, regulators started to have heart palpitations at the thought of losing control of mass and dimensions, not knowing what sorts of weird and wacky heavy vehicles were likely to emerge. After more than two years of operation of the scheme, what do you think is by far the most common design to pass through the system? The answer is the standard 6×4 truck and quad dog with tipper bodies, albeit a couple of feet over the normal 19-metre overall length limit and with additional gross mass. Quite an anti-climax, you might say. But I see this as an opportunity too good to let slip by. Allow me to explain.
First of all, consider the benefits of this vehicle. Despite its imperceptible difference from a prescriptive truck and dog, the typical PBS truck and dog is rewarded with a generous mass increase, based on the sum of individual axle group mass limits, that amounts almost entirely to additional payload when operating on B-double routes and gazetted local government roads. Being of the same axle silhouette as a 19-metre B-double, it has the same loading privileges without the additional tare mass, capital cost and operational difficulties. It has better manoeuvrability and flexibility for tipper work, being easier to swap and drop trailers, and it is better suited to road construction and other types of work where it is required to spread the product while unloading. And unlike the 19-metre B-double, it has the PBS safety tick of approval.
One drawback, however, is that it costs a pretty penny to get one operating under the PBS scheme. Despite this, the industry is still taking them up in moderate numbers. Maybe it’s time for regulators to sit down, look at what all of these rigs actually look like, and put them into the public domain under prescriptive regulation for all to use freely.
“Maybe it’s time for regulators to sit down, look at what all of these rigs actually look like, and put them into the public domain under prescriptive regulation for all to use freely.”
The idea is not new. When the Canadians introduced a number of higher productivity heavy vehicles in the 1980s, they used PBS-style assessments to sort the good from the bad when considering all of the different design options, and then simply put in place some prescriptive mass and dimension envelopes to capture the more desirable configurations.
I say we let the truck and dog be the first of many future ‘Prescriptive PBS’ spin-offs by continuing to use PBS as the petri dish for developing more advanced species of prescriptive heavy vehicles. While I don’t think it’s generally a good idea for governments to ‘pick winners’, I believe that when you have a strong market-driven trend staring you in the face, there has to be something right about doing just that.