Motorists are advised to plan ahead for westbound closures on the Causeway section of the Northwestern Motorway this weekend.

The NZ Transport Agency says State Highway 16 will be closed from Great North Road to Patiki Road between 8pm on Saturday 16 July and 10am Sunday 17 July.

The Rosebank Road off-ramp will also be closed.

The closures are to allow the construction team to pour concrete to connect the existing bridge at the city end of the Causeway to a newly built bridge which runs alongside it carrying eastbound traffic.


"The concrete takes about 12 hours to harden and strengthen and because vibrations from passing traffic can affect that process all the westbound lanes need to be closed," says Brett Gliddon, the Transport Agency's Auckland Highway Manager.

"Motorists planning to use the Northwestern Motorway should factor extra time into their journeys as they will need to follow the detour route through Great North Road, Rosebank Road and Patiki Road before re-joining the motorway."

All lanes heading towards the city will stay open throughout the weekend, along with the Rosebank Road on-ramp and the Northwestern Cycleway.

Those motorists wanting to travel to Te Atatu should continue down Ash Road rather than re-join the motorway at Patiki Road.

If the weather is bad the work will be rescheduled to the following weekend, 23 and 24 July.