Tow trucks struggled through heavy traffic, caused by breakdowns on the Southern Motorway during the Friday rush hour ahead of a one-off long weekend.
Waka Kotahi says motorists should expect 35-minute delays travelling southbound on State Highway 1, as traffic could stay heavy into the evening.
A breakdown blocked the left southbound lane just after the Papakura off-ramp, the transport agency reported about 4pm.
Towing services were "still making their way through heavy traffic" to the breakdown at 5pm.
A separate breakdown happened on the same motorway just after the East Tamaki off-ramp, which has since been cleared.