But he believed a new structure to be introduced in August will be less effective in allocating charges to operators of vehicles inflicting the most damage to the country's roads.
A new system of charging according to a simplified range of weights would hit couriers and express parcel deliverers with disproportionately higher costs than operators of heavy vehicles.
Instead of being charged according to the actual weight of their loads, operators would have to pay fees based on their vehicles' maximum legal carrying capacity and axle configurations.
Because long-distance courier vehicles "bulked out" with relatively light goods, well before reaching maximum weights, their operators would be penalised unfairly.
"There will be no consideration given to operators who specialise in transporting lighter loads," Mr Speers said. "Our trucks will be assessed on the same basis as heavy logging vehicles - even though our loads are much lighter, we will be charged the same rate."
Freightways chief executive Dean Bracewell questioned a Government claim that the new system would be "revenue neutral" after plugging holes in the system.
He said his company ran a range of vehicles and had not been able to identify any reduced charges to counter-balance cost rises.
He believed it unfair for the Government to penalise a large cross-section of the freight industry rather than targeting a minority of rogue operators.
Imposing an across-the-board tax on diesel would have ensured nobody avoided paying their fair share.
But the Ministry of Transport says 36 per cent of diesel is used for off-road purposes such as on farms, and it would be unfair to impose a blanket tax to raise revenue for the national land transport fund.
Operating a refund system would be costly and cumbersome, it says.
A ministry spokeswoman said the existing system, under which vehicle operators had to estimate maximum weights to be carried over distances covered by road-user charges licences, was also problematic.
"It can be difficult to predict the weight to be carried in advance, and scales are not always available at loading sites," she said.
"Changing the definition of licence weight will greatly simplify administration for both industry and government agencies.
"It also means that the door will close on weight-based evasion because an operator will no longer be able to under-estimate the weight of the vehicle and purchase an incorrect [road-user charges] licence."
