A teenager has been fined $150 and severely reprimanded for risking his life riding on the back of a freight truck through Lyttelton tunnel.
The hi-jinks started late last Thursday night when the 18-year-old got out of a car and climbed onto the back of a 40ft container being taken to the port.
The truck had stopped at the Christchurch side of the tunnel while waiting for a lane to open due to maintenance.
The truck driver was unaware he had a passenger.