The work is on the State Highway 8 Alexandra bridge and three bridges on SH6 in the Kawarau Gorge, between Cromwell and Queenstown. When completed, the bridges will be capable of carrying high productivity motor vehicles (HPMVs), which are trucks permitted to carry loads of up to 58 tonnes.
NZTA project team manager Simon Underwood, said HPMV-permitted trucks with loads capped anywhere between 45 tonnes and 58 tonnes were expected to use the bridges once this work was done.
Fulton Hogan was strengthening the Alexandra bridge at a cost of $770,000. Work on the Kawarau Gorge bridges would cost $840,000. At the Roaring Meg bridge, the work included abutment protection to ensure the bridge remained serviceable for all traffic. At the Gentle Annie bridges, steel rods were being placed on their undersides to make them strong enough to handle HPMV trucks.
At the Kawarau River (Victoria Bridge), extra steel plates were being added. All work is planned to be completed by June 30, 2015.
As freight volumes grew, the availability of the high productivity routes for the use of HPMVs would help reduce freight journeys by up to 20%, Mr Underwood said.