KEY POINTS:
Drivers heading out of Auckland in two directions face delays from motorway construction work in coming days.
An extended closure of all northbound lanes of the Northern Motorway through the Onewa interchange from 8pm on Saturday until noon on Sunday has prompted a plea from the Transport Agency for drivers to avoid the area if possible.
That is to allow workers to complete their demolition of the old Onewa Rd bridge, which has been replaced by two separate traffic ramps to and from the motorway.
Those unable to avoid travelling then, or during a second closure from 10pm on Sunday until 5am on Monday, will have to avoid the demolition site by leaving the motorway at the Onewa Rd exit and then rejoining it via the interchange's northbound on-ramp.
That raises the prospect of long queues at traffic lights on Onewa Rd.
Drivers wanting to travel to or from Auckland Airport overnight on Sunday, Monday or Tuesday are also being advised to allow an extra 30 minutes in case of delays on detours around a bridge due for demolition over the Southwestern Motorway.
The full motorway beneath the Rimu Rd bridge on the Mangere side of Manukau Harbour will close for 2km between 9pm and 5am each night, as part of the Transport Agency's $230 million harbour crossing duplication project.
Traffic will instead have to use Mahunga Drive to the airport, or Coronation Rd in the opposite direction.
And at the end of the Northwestern Motorway, from Monday morning a giant temporary roundabout opens to divert traffic from a bridge construction site until 2010.
The bridge will be built inside the roundabout, as a local traffic link over the motorway, which is to be lowered as part of a $220 million project to extend State Highway 16 to Brigham Creek Rd and build a 6km motorway section through Hobsonville.
