Full cost of heavier trucks questioned

The Government hopes to roll out a permit system for heavier trucks from February. Photo / Richard Robinson

Influential organisations representing engineers and local councils are questioning the economic justification for introducing heavier trucks to the country's roads and bridges.

They fear the road user charges system will not recover the full costs of extra damage from trucking firms for loads of 53 tonnes or more, leaving ratepayers and taxpayers to make up the shortfall.

Both the Institution of Professional Engineers and Local Government NZ claimed yesterday that not enough analysis of the costs of allowing heavier loads had been undertaken to demonstrate whether productivity gains would outweigh these.

"There is considerable concern that analysis of the costs to date has not been adequate," said the institution director of public policy Tim Davin of a permit system for loads heavier than the existing limit of 44 tonnes, which the Government hopes to roll out from February.

"It cannot be argued that it will improve productivity without such an analysis."

His concern was reinforced by Local Government's manager of development and infrastructure, Geoff Swainson, who feared greater damage to councils' roads "on which the pavements are generally thinner than on state highways."

"Even now, without extra loads on them, councils are facing huge liabilities for bridge replacements."

Transport Minister Steven Joyce said last month, in announcing the proposed change, that trials approved by the previous Labour Government on selected roads and other research had indicated a potential annual increase in gross domestic product of $250 million to $500 million a year.

But Mr Swainson said that without taking into account the full costs of heavier loads, including pavement repairs and potential road widening, the benefits risked being substantially over-stated.

His concern has been heightened by advice from the Transport Agency that a preliminary cost estimate of $85 million to $100 million to prepare for the move would cover only 300 bridges on state highway routes most frequently used by heavy trucks.

But Road Transport Forum chairman Simon Tapper, of Auckland trucking firm Tapper Transport, said his industry was keen to pay its way and would support measures to ensure local councils received adequate reimbursement for any extra damage.

He was confident sufficient checks and balances would be added to the system, once the Ministry of Transport considered all submissions due in by Friday, including the possibility of requiring a satellite positioning system to ensure trucks stayed on routes.