Motorists were also being warned to expect delays following a crash in the Victoria Park Tunnel in Auckland.
The incident blocked the left lane of State Highway 1 northbound just after 4pm. It was cleared by 5pm.
NZTA has warned those heading north through the tunnel to expect congestion following the crash as peak-hour traffic sets in.
Traffic was also heavy citybound between Northcote Rd and the city.
Things weren't looking much better for people heading home on the Northwestern Motorway, which was heavy westbound between Western Springs and Lincoln Rd and moderate to heavy citybound between Royal Rd and Lincoln Rd.
Traffic was also heavy on the Southern Motorway citybound between Princes St and Market Rd.