Further north, a truck rolled over, spilling diesel on East Coast Rd, near Rodeo Drive, Redvale, about 11am.
Fulton Hogan staff were on site about 1pm waiting for diesel truck to clear the spill, a police spokeswoman said.
Motorists in the Redvale area should expect delays or avoid the area if possible, NZTA said.
A 10.30am collision between a car and a motorcyclist that blocked the middle, city-bound lane of the Southern Motorway after the Penrose Rd overbridge was still causing significant delays at least an hour after it was cleared.
The motorcyclist was taken to hospital, a police spokeswoman said. No one was believe to have been injured in any of the other crashes.
The crash affected traffic in both directions, NZTA said.