One of the country's main motorways is too weak to take the new giant trucks that are set to hit the road.
The Transport Agency (NZTA) says it will need to recondition a dozen sections of Auckland's Southern Motorway before the road meets the standard required for larger trucks.
Currently, the maximum permitted weight is 44 tonnes, but trucking companys are keen to use 53 tonne trucks.
NZTA state highway manager for Auckland, Tommy Parker, says it is assessing the structural weaknesses to see what work will need to be done.
He says some will need only minor strengthening, but others will need more reinforcing, which will be revaled when the feasability study is completed.
Mr Parker says, depending on the level of repairs, large trucks could use the motorway in a year's time.
The Auckland Harbour Bridge is also being assessed.