A witness to the crash told the Herald the accident looked "pretty bad".
"A car has hit the bank and is on its roof ... it looked like people were stuck inside and construction workers nearby were trying to break the windows to get them out."
A second witness said the car was on its side with a man trapped inside as first responders tried to get him out.
"They've said the road will be closed for several hours."
A police spokesperson confirmed this, saying it was expected the road would be closed "for some time".
A Wellington Free Ambulance spokesperson told the Herald they attended the crash, but had no further information, referring the Herald to police.