An oversized truck which struck an overbridge on the southbound lane of State Highway 1 this afternoon, has now been cleared, according to Waka Kotahi.
Waka Kotahi reported the truck had crashed into the Penrose Rd overbridge on the motorway's left lane at 2.35pm this afternoon.
The transport agency said it expected the left lane to be closed for the majority of the afternoon.
Motorists were urged to either use an alternative routes on SH16 or SH20, or delay journeys this afternoon due to heavy traffic on both lanes of the motorway.
Structural engineers had been sent to the scene to assess potential damage to the bridge, Waka Kotahi said.
At 4.30pm, Waka Kotahi reported the crash had been cleared but motorists were warned to expect 45 minute delays on southbound lanes.
The transport agency said there would be a full closure of SH1 southbound lanes from Greenlane to Mt Wellington between 11.10pm and 5am tonight.