Trucks could be allowed to carry heavier loads on New Zealand's highways by early next year.
The Government on Monday put out a proposed rule change for consultation that would allow road transport operators to apply for permits to carry heavier loads on certain routes.
It would see the maximum load increase from 44 tonnes to 50 tonnes on approved routes.
Transport Minister Steven Joyce says the change would mean fewer trucks on the roads, as well as reduced freight costs for exporters.
Mr Joyce says it is hoped the change will be signed off by the end of this year, with permits available from early 2010.
But the Green Party says plans to allow heavier trucks on roads could undermine the movement of freight by rail.
Transport spokesperson Jeanette Fitzsimons is concerned the move will slow down the shifting of freight from road to rail, which she believes will be more energy and economically efficient in the long run.
Ms Fitzsimons says heavier trucks will do more damage to roads and there should be tight rules regarding which roads they can use.