Motorists driving into Wellington city face delays after a 30-minute closure to the Terrace Tunnel.
The tunnel had been closed when a tractor trailer unit triggered the over height alarm barriers in the tunnel on State Highway One into the capital.
That has created a build-up of traffic travelling into the city and even though the tunnel is now open the Transport Agency says it will take some time to clear the congestion.
It is advising commuters to either catch the train to work or delay their travel into the city.