The highway was closed overnight due to a chemical spill, Waka Kotahi NZTA confirmed, causing major traffic delays for motorists returning home after the long weekend.
Detours were in place around the accident site.
Also yesterday, a boy was airlifted to Starship children's hospital in critical condition after being struck by a car in rural West Auckland.
A chopper was sent to Helensville at 12.04pm, Westpac Rescue Helicopter spokesman Lincoln Davies said.
Davies said the boy was involved in a "vehicle versus pedestrian accident" but he could not confirm the child's age.
A boy was air-lifted to Starship children's hospital in critical condition after being struck by a car in rural West Auckland. Photo / Supplied Police confirmed they also attended.
Another person died after a crash on SH26/Paeroa Kopu Rd on Saturday.
Police responded to a serious crash involving a car and a motorcycle about 2.30pm.
The road was closed for some time as a result of the crash.
On Sunday, Invercargill police appealed for information to locate the vehicle involved in a hit-and-run accident early that morning.
A man was struck by a vehicle about 6.15am on Marama Ave South in Otatara
And two people were seriously injured after a late-night crash in a West Auckland suburb on Sunday night.
Police said a person was kidnapped from an address in New Windsor and forced to withdraw money from an ATM machine.
Two people were transported to Auckland City Hospital following the collision in New Windsor overnight. Photo / Hayden Woodward A man was arrested after crashing a car with the kidnapping victim still inside at the intersection of Richardson and Maioro Rds.
The alleged offender collided with a vehicle driven by a member of the public, causing significant damage to both cars, police said.
A 20-year-old man appeared in the Auckland District Court yesterday on a raft of charges.
