The Southland tipper: hubodometer, RUC weight and a weighbridge
Callum operates a 2016 rigid tipper in Southland. The truck's GLM is 22,000 kg. Four months ago he bought a road user charges (RUC) licence for 10,000 km at a RUC weight of 22,000 kg, when the hubodometer read 138,000 km. Last month the hubodometer failed and was replaced. The old unit read 141,880 km when it came off; the new unit started at zero and now reads 3,420 km. Callum wrote the old reading on the back of a docket in the glovebox and told nobody. He has also taken on a shingle contract that requires the truck to run at 23,600 kg on the road, and has been doing it for two weeks while the RUC licence still shows 22,000 kg. On Friday a transport inspector weighs the truck at 23,550 kg.
1. How many kilometres of RUC has Callum used since the licence was bought, and what does the hubodometer replacement actually change?
Read the worked answer
Work from the readings. The licence was bought at 138,000 km and covers 10,000 km, so it runs out at 148,000 km on the original meter.
- On the old meter: 141,880 − 138,000 = 3,880 km.
- On the new meter: 3,420 km.
- Total: 7,300 km used, leaving 2,700 km of licence.
So there is no RUC distance offence yet - the measurement trap is a distraction from the real problem. What the replacement changes is the evidence chain. The RUC licence is tied to the vehicle's distance recorder, and a new unit starting at zero breaks that chain unless the reading at removal and the new unit's starting reading are recorded and notified. A scribble on a docket in the glovebox will not survive an audit, and the operator carries the burden of proving distance travelled. Callum should transfer both readings onto the RUC licence and notify his RUC collector now.
2. What are the consequences of running at 23,550 kg, and can Callum simply buy a 24,000 kg RUC licence to fix it?
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No, and this is the trap in the scenario. RUC weight is set from the vehicle's gross laden mass, and a licence cannot be bought at a weight above the GLM recorded for the vehicle. The truck is rated at 22,000 kg, so 22,000 kg is the ceiling regardless of what the shingle contract wants.
Running at 23,550 kg creates two separate offences:
- RUC: operating above the licensed RUC weight means there is no valid RUC licence for the weight actually carried. It is assessed on the heaviest weight the vehicle is likely to operate at, not just the weight on the day.
- Mass: 23,550 kg is 1,550 kg above the GLM, which is an overload in its own right, independent of RUC.
The correct response is to cut the payload so the truck runs at or under 22,000 kg on the road, and re-quote the contract on that basis. If Callum genuinely needs more weight, he needs a bigger truck, or an engineer's re-rating with a new CoF - and only then an RUC licence at the new figure.
3. What should Callum do about the hubodometer record, and why does it matter at the next RUC licence purchase?
Read the worked answer
Two things, in this order.
Fix the record. The hubodometer is the vehicle's distance recorder and the RUC licence is measured against it. When a unit is replaced, the closing reading and the new unit's starting reading must be recorded and notified to the RUC collector, with the record kept with the licence. Do it in writing now, while the docket is still legible, rather than reconstructing it later.
Understand why. At the next licence purchase the seller needs to know how many kilometres have been used. Without a documented change, the distance on the new meter cannot be reconciled with the old one, and an inspector can assess the distance on the assumption the vehicle has been running unchecked. An unreconciled or missing record can be treated as failing to keep the required records. The 2,700 km of remaining licence is only defensible if the 7,300 km already used is documented - the arithmetic is in Callum's favour, but only if he can prove it.