Motorists on State Highway 1 between Palmerston and Oamaru should allow extra travel time from next week as work starts to strengthen and widen the Kakaho Creek Bridge north of Hampden.
The narrow and curved bridge could be a challenge to negotiate, especially for truck drivers, NZTA project team manager Simon Underwood said.
When work is completed, the bridge will be able to carry High Productivity Motor Vehicles with loads capped anywhere between 45 tonnes and 58 tonnes.
Because of the constraints of the highway in the bridge location, temporary traffic management, including a lower speed limit, will be in place.
Mr Underwood said, at times, only one controlled traffic lane would be available.
Minor works to improve the bridge's alignment will also be undertaken as part of the job.
The work is due to be finished by the end of September.
