Photo: RNZ / Rebekah Parsons-King
A crash closed the Terrace Tunnel, one of the main entrances to downtown Wellington, just before 1pm.
The Transport Agency said it was shut in both directions.
It re-opened at 2pm, however, motorists were being warned to expect delays accessing the tunnel and travelling through the city as congestion cleared.
The police said three vehicles were involved in the smash and there were no reports of injuries.