Before 2006, the established procedure for determining the chassis rating of a Japanese-import used HMV was straightforward. Brian Young Commercial Vehicle Information Services, based in Hamilton, would obtain vehicle-specific manufacturers’ design ratings from Japanese sources.
This all changed with the Heavy Motor Vehicle Brake Rule 2006. We moved then from a chassis-rating system, where the vehicle was rated according to its engineering design capabilities, to a system based on the vehicle’s previous use in Japan.
This has led to an inequitable situation for used HMVs that reduces operators’ choice, and their ability to purchase suitable used vehicles!
The IMVIA has long been aware that some new-vehicle importers have access to documentation from manufacturers that lets them allocate commercially desirable GVM ratings, as opposed to the vehicle’s maximum design rating.
Why would a commercial buyer want a lower GVM on a vehicle? There are many reasons, including RUC, driver licence, and more. We understand that lower GVMs have always been within manufacturers’ known tolerances for the vehicles, and have not caused road safety to be compromised.
We have proposed that NZTA allows an alternative source for initial GVM ratings that will let the used heavy vehicle industry compete on a level playing field.
And what is that alternative source? Glad you asked!
Rely on the experts; ask the transport engineers!
There is plenty of expertise among heavy vehicle certifying engineers who are members of IPENZ’s HVE group.
These engineers are qualified to certify most aspects of heavy vehicles, and provide ratings for modifications and alterations. That makes them uniquely qualified to advise on acceptable GVMs.
Heavy vehicle certifying engineers should be able to rate a commercial vehicle’s GVM based on good engineering practices, their assessment of the vehicle, relevant safety considerations and the application of physics.
Uprating would be limited to the maximum load a vehicle can safely carry within design criteria.
Down-rating would simply be limited by logical consideration of the vehicle (and its application), since heavy vehicles are designed to operate safely in the range between tare and GVM.
How would our proposed system be applied? We’ve suggested this approach:
Where manufacturer specifications are available, the GVM should be based on:
The stated GVM, or
When relevant, the alternatively specified permissible axle loadings.
Where manufacturer specifications are not available the GVM should be based on:
The GVM specified in export documentation, or
The assessment and professional opinion of a heavy vehicle certifying engineer.
This would go a long way towards levelling the playing field for commercial vehicles. It is also a logical extension of heavy vehicle certifying engineers’ ability to rerate vehicles. And it formalises the ‘pick and mix’ rating that already occurs in the sale of some new commercial vehicles.
Even though this has been an issue for many years, NZTA has not yet placed it on its work programme.
The industry and vehicle operators need NZTA to escalate this on its work-priority list. Sooner, rather than later!
