Two lanes have now been opened southbound on SH1 at Ellerslie following a serious crash under the Penrose Road bridge.
Lanes two and three are now open however there are queues back to the city.
The third lane will reopen once the road surface has been repaired to make it safe for motorists and motorcyclists.
The Ellerslie Panmure onramp Southbound remains closed.
The truck and trailer which hit the Penrose Road bridge has been cleared.
The motorway over height detection system was operating at the time.
Delays remain in the area and motorists are advised to use alternative routes.
North Shore traffic should consider using SH18, SH16 onto SH20 to head to South Auckland and the airport.
Traffic heading south out of the city consider taking the Ellerslie Panmure off-ramp onto the Ellerslie Panmure Highway and using Great South Road and the Mt Wellington Highway.
