One person has died in a crash on the Southern Motorway, near Drury, that closed the motorway in both directions today.
One lane in each direction between Papakura and Drury is now open, Waka Kotahi NZTA said.
Emergency services responded to reports of the single-vehicle crash at the Bremner Road overbridge at about 10.30am.
One person died at the scene, police said.
The motorway was closed while the scene is cleared and damage to the overbridge is assessed.
Traffic will continue to be diverted this afternoon, police earlier said. Waka Kotahi also advises motorists to use Great South Rd via Papakura or delay travel.
“Avoid this area, or expect long delays.”
The transport agency has also said that the motorway will fully close to motorists between 9pm tonight and 5am tomorrow.
A signposted detour via Great South Rd will be in place.
Crews will be installing barriers and carrying out repair works to the Bremner Rd overbridge.
Bremner Rd overbridge will remain closed for the rest of the day, and throughout tonight.
Just before 12.30pm, a police spokesperson said the motorway would be closed for around an hour while the scene is cleared and damage to the overbridge is assessed.
Southbound traffic is being diverted off the motorway at Beach Rd and northbound traffic is being diverted at the Drury exit.
Fire and Emergency Northern is freeing a trapped person, believed to be the driver, from the cab.
Waka Kotahi media manager Kaity Alexander said a team member was on the way to the overbridge to assess it.
A police spokesperson said emergency services were called to the crash around 10.30am.
“Initial indications suggest one person has received critical injuries.”
The closure is also affecting public transport - buses that usually travel through the area will detour around the stretch of motorway until further notice.
Traffic is gridlocked on both sides of the motorway near the crash.
Before the motorway closed, traffic was inching past the crash scene and a large emergency response and the cab of the truck smashed against the overbridge central post could be seen.
Meanwhile, a car flipped on Auckland’s Southwestern Motorway.
The crash is blocking two southbound lanes.
Waka Kotahi is advising motorists to use an alternative route or to expect delays.
The annual event means closures for some lanes on the city's harbour bridge.