The man who spent 10 hours on top of pipes at the entrance of Wellington's Terrace Tunnel has pleaded guilty to dangerous driving and possessing a knife.
The man was charged with dangerous driving causing injury, and possession of an offensive weapon after the incident in January.
The 31-year-old appeared in the Wellington District Court this morning, where he pleaded guilty to the charges.
The man, who has interim name suppression on a mental health basis, crashed into another car while driving the wrong way on State Highway 1 on the city end of the tunnel.
A short time earlier he had sped away from police. He was travelling north in the south bound lane when he hit another car which was driving the correct direction towards the city.
Armed with a knife, he then climbed onto the pipes above the tunnel and stayed there for the next 10 hours.
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.
He eventually came down around 10.30pm and was taken away to be medically assessed.
He did not explain his offending to police.
At the first call of the matter in court, the man was still being held in a psychiatric unit in hospital. He is now on bail.
He was remanded to June for sentencing, and for a final decision on name suppression.
At the time of the incident, 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 AOS, police negotiators and dog teams assisted and all possible tactical options were considered 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," said Bensemann.
He said the man had been carrying a knife which he used to slash his forearms. Blood splatters were visible on several of the pipes.
The pipes were 1m wide and 12m long, making it "unrealistic" for police to engage with the man.
Police closed the tunnel following the incident and organised four double-decker buses to be parked underneath the man, reducing the drop space between him and the ground.