As part of the Christchurch Northern Corridor (CNC) project, the Waimakariri Bridge is being widened and strengthened so it can carry two extra traffic lanes and a new clip-on cycleway.

Work will start at the end of the month but will be done off-peak to reduce impacts on drivers. The project will take around 16 months to complete.

The Waimakariri Motorway Bridge, in fact made up of two separate bridges, north and southbound, will each gain an extra lane on the inside of the pair. When they were built in the 1970s, provision was made for three lanes on each, however bridge construction standards have changed since then, so further strengthening is needed to take the additional weight and width, says NZ Transport Agency Portfolio Manager, Colin MacKay.

A clip-on cycleway/shared path will be added on the outside of the southbound bridge.

From Monday, 27 August, CNC’s construction crew will start drilling the more than 11,000 holes needed on the existing bridge decks to attach the new decks. They will also attach strengthening beams to the top of the bridge piers.

“During most of the work there will be little construction impact on bridge traffic,” says Mr MacKay. “Our crews will be working in the reserve area in between and underneath the two bridges and in part of the river bed. To keep our crew and motorists separated and safe we will need to reduce, first the north and then the southbound bridge to one lane at off peak times. Temporary speed limits will also be in place.

“There will be a greater impact on drivers when we start placing the new bridge beams by crane in November. We know this is a busy commuter bridge so we will only do this during off peak hours and at night.

“Our work will mean some changes in the Waimakariri River Regional Park area under the bridges. We are working closely with the local rangers to keep this area open and safe.”

For further background and details on this project, read the latest newsletter here: https://www.nzta.govt.nz/assets/projects/christchurch-northern-corridor/CNC-Waimakariri-Bridge-project-overview-20180813.pdf(external link)