From next year, bigger trucks, loaded to their 50-tonne capacity, will be allowed to use Central Otago roads after the Central Otago District Council approved the move this week.
Speaking to the council, New Zealand Transport Agency senior investment adviser Gordon McDonald said increasing the maximum load from 44 tonnes to 50 tonnes was an ''economically viable option without upgrading roads''.
Initially, that meant more freight would be able to be carted by fewer trucks, although ''freight task'' was predicted to double in the next 20 years, he said.
The trucks capable of carrying 50 tonnes are 23m long, 3m longer than their 44-tonne-carrying counterparts. They also have an extra axle.
Cr Shirley Calvert said the extra 3m of truck would make it that much harder to pass them and there were too few passing areas in the district.
Council roading manager Julie Muir said the trucks were already here, they were just not permitted to load to capacity yet.
''The bigger trucks are here, they are legally allowed to operate on our network. The question is whether we let them load up.''
They have been legally allowed to operate on State Highways when loaded to 50 tonnes.
Ms Muir said allowing the heavier vehicles to operate on local roads would mean Central Otago residents would be able to ''reap the benefits of reduced freight costs of goods brought into the district, and assist businesses who move freight out of the district to remain competitive''.
Mr McDonald said because the bigger trucks were new, they had more safety features than the older ones.
In her report to the council, Ms Muir said consultants had been hired to assess the effects of the heavier vehicles on road pavements. They concluded ''the overall risk of increased pavement deterioration ... is to be assessed as low''.
Bridges which already had weight restrictions on them would be excluded from routes the new trucks could take. After a suitability screening process of bridges in the district, the only one left in question was over the Clutha River at Millers Flat. The NZTA would fund further analysis of it but if it required an upgrade, the council would bear that cost.
The analysis is expected to take place between January and March.
The larger trucks require an annual permit which the agency will issue on behalf of the council, as well as bearing any costs involved.
The Central Otago District Council was the first in Otago and Southland to consider introducing the rule.
