All lanes on Auckland's northern motorway open again after road repairs overnight

All lanes on Auckland's northern motorway (SH1) are open again this morning. Image / NZTA

All lanes on one of Auckland's busiest motorways are open again after urgent road repairs had to be carried out.

The northern motorway (State Highway 1) is now full open, after lanes in each direction had to be closed from yesterday afternoon, when the road surface lifted.

The raised surface resulted in what was described as a "significant speed bump" for vehicles travelling between Greville Rd and the Upper Harbour Highway.

Waka Kotahi NZ Transport Agency said the uneven surface was caused by road construction crews working under it.

"They were pumping grouting material which became blocked and seeped out under the road surface - causing it to lift," a spokesman said.

FINAL UPDATE 7:30PM
Northbound delays on the Northern Mwy continue to ease, with a tail now at Tristram Ave. One lane (each way) btwn Upper Harbour Hwy & Greville Rd will remain closed until 9pm when all lanes close for emergency repairs overnight. ^TPhttps://t.co/IPHjZyuVoR

— Waka Kotahi NZTA Auckland & Northland (@WakaKotahiAkNth) December 1, 2020

Road authorities said the overnight repairs involved stripping the road surface to remove the grout material and paving it again with asphalt.

"Waka Kotahi thanks motorists for their patience and understanding."

Motorists were alerted to the situation at 2.40pm yesterday.

It caused traffic mayhem during rush hour as people headed home for the day and people were urged to take an alternative route or expect long delays.

By 7.30pm, northbound congestion had started to ease - with a tail reaching Tristram Ave by that stage.