The crash blocked off multiple northbound lanes on the Southern Motorway, near the Khyber Pass off-ramp, just before 10.20am. Photo / Supplied
Footage at the scene show long queues building behind the crash. At one point, delays backed up towards Ellerslie. The crash was cleared by about 11am.
The NZ Transport Agency said, however, motorists could still expect delays as congestion eases.
St John confirmed they had been called to the area about 10.14am and treated a person in a critical condition.
A spokeswoman confirmed: "We have sent multiple units including one ambulance, a prime doctor, a first response unit, a rapid response unit and one helicopter from Whāngārei".
The rider is being taken to Auckland City Hospital's emergency department for treatment.