Prominent investment banker Guy Hallwright has gone on trial on charges of allegedly causing bodily harm in a road rage incident in Auckland on September 8, 2010.

He pleaded not guilty before Judge Raoul Neave and a jury at the Auckland District Court.

Hallwright was charged with one count of causing grievous bodily harm to Song-jin Kim (58), or an alternative charge of causing injury with reckless disregard.

A senior analyst for Forsyth Barr, it is alleged Hallwright was driving his car in Mt Eden and hit Kim with it after the two had an altercation. It is alleged he drove over Kim, breaking his legs and shattering an ankle.

Kim was the first witness and limped slowly into the witness box.

He told the court he was behind a car, containing a man and a woman, at traffic lights. The lights changed to green but the car did not move off.

"Two people were arguing, they didn't go," Kim said, adding that other drivers sounded their horn and made gestures.

Kim said Hallwright "turned around and showed me the finger, I said not me'." His evidence will continue.

Crown prosecutor Ross Burns told the jury that Kim had been behind Hallwright at the traffic lights. When they turned green Hallwright did not move and so Kim, in a Mercedes Benz behind, sounded the horn.

When the traffic moved, Hallwright pulled over to let his daughter out of the car. Kim pulled in front of him.

Hallwright got out and went to Kim's car and opened his door and shouted at him.

Burns said Hallwright then returned to his car and then Kim came out of his car, walked back to Hallwright's car and banged on it.

He said Hallwright then drove off, running over Kim and leaving him with two broken legs and a shattered ankle.

Burns told the court Hallwright was an angry man and had acted recklessly.

"This was a man who was angry, he turned his car into a one-and-a-half ton weapon," Burns said.

The court will hear from a 111 emergency call Hallwright made after driving off. He said he would return to the scene but only after dropping his daughter at a music-recording studio. He was told to return immediately.

Hallwright told police he thought Kim was threatening and said he believed Kim would jump aside as his car drove off.

Hallwright, represented by Paul Davison QC, fought a long battle for name suppression, going unsuccessfully to the High Court.

The crown will call 20 witnesses in a trial expected to last five days.

- © Fairfax NZ News