The man, who was armed with a knife, climbed on to the pipes after colliding with another car while driving the wrong way on State Highway 1, city end of the tunnel, about 12.30pm yesterday.
He eventually came down about 10.30pm and was taken away to be medically assessed.
Police closed the tunnel and spent the afternoon and evening trying to negotiate with him, during which time he refused anything to drink or eat and cut himself with the knife.
Yesterday, Wellington District Commander Inspector Chris Bensemann said the number one priority during the incident was ensuring the safety of officers, the public and the people involved.
Wellington District Commander Inspector Chris Bensemann said the number one priority during the incident was ensuring the safety of officers, the public and the people involved.
More than 20 staff including members of the Armed Offender Squad, police negotiators and dog teams assisted and all possible tactical options were considered in order to safely resolve the incident.
"In the end this became a matter of patience and communication and we are glad the incident was resolved without further injury," Inspector Bensemann said.
Police closed the tunnel and organised four double-decker buses to be parked underneath the man, reducing the drop space between him and the ground.
Bensemann thanked Fire and Emergency NZ, Wellington Free Ambulance and Metlink for their assistance in "hot and tiring conditions" throughout the incident.
