The State Highway 1 Redoubt Rd on-ramp at Manukau has re-opened following an oil spill from an earlier crash, but delays should be expected.
The NZTA earlier alerted commuters to use alternative routes after the Redoubt Rd southbound on-ramp, and link to SH20 northbound, was closed shortly before 6am.
It asked commuters to use Lambie Dr as an alternative while the clean up was under way.
The earlier closure is likely to cause delays as thousands of commuters begin to head into work.
A crash around 6.30am on State Highway 1 near Kaiwaka also caused slight delays through the area.
Police reported that a vehicle hit a barrier, but no injuries were reported, however several other vehicles stopped to assist.
NZTA advised that delays in the area were possible, and to allow a little extra time.