Transport Minister Stephen Joyce is considering a change to the Land Transport rule that would allow a logging truck, on some routes, to be 10% longer and 20% heavier than at present.
The change would allow logging contractors to increase the maximum weight of fully laden trucks by nine tonnes to 53 tonnes, and increase the overall length, including overhang, from 20m to 22m.
The Forest Owners Association is pushing for the overall length to be 24m, arguing it would allow the transport of more 6m logs favoured by China, and points out in Europe the maximum is 25m.
For City Forests chief executive Grant Dodson, the change cannot come soon enough, with the prospect of a 10%-20% saving in transport costs for logs being transported between Dunedin City Council-owned forests around Lake Mahinerangi and Port Otago.
Mr Dodson said the main advantage of the change was logging trucks would be able to carry three bays of logs rather than two, and for motorists it would mean fewer trucks on the road.
When the regulations are in place, roading authorities will have to identify which routes are suitable for the heavier trucks before issuing permits to transport operators.
The two main concerns are expected to be the effect on bridges and road surfaces.
When public submissions were called for last July, Local Government New Zealand noted bigger trucks would generate national benefits, but costs would "appear to be incurred regionally" and it considered the costs of the new rule "should not have to be met with an increase in rates".
It considered the move would "accelerate damage to road pavements" - particularly local roads with thinner pavements - and bridges and culverts might need to be strengthened on permitted routes.
Mr Dodson said as far as City Forests was concerned, the main question would be the suitability of roads between its Waipori forests and State Highway 1, in particular Shaws Hill Rd and the Berwick-Henley Rd.
In a letter promoting the change, Forest Owners Association chief executive David Rhodes said the cost of transport from forest to mill or wharf amounted to about 25% of the value of a log.
Mr Rhodes said the change was expected to reduce truck journeys by 16%, reduce fuel use by 20% and increase GDP by between $250 million to $500 million a year.
A Ministry of Transport spokeswoman pointed out the trucks would be no wider or higher and the proposed increase in length was "small".
"Longer trucks can be safer because the load height can be reduced and the vehicle is therefore more stable during cornering."
The rule change is to occur in February, subject to final Government approval.
