"The public is entitled to expect to be safe in taxis; parents should be able to trust that their teenage children will be safe in taxis," Judge Wilmoth told Rana.

"This girl's safety was entrusted to you when the people who helped her gave you the money for her fare, to take her safely home.

"Instead you violated that trust when you raped her."

The girl had been drinking vodka at a friend's house before sharing a taxi with a male friend to a railway station in Melbourne's east at about 1am on November 4 last year.

Her friend continued home in the taxi after dropping her at the station, not realising she would be stranded.

The teenager had no money and no way of getting home as trains had stopped running for the night.

Depressed and suicidal, she accepted two valium tablets from a couple she came across whom she described as junkies before swallowing two months' supply (up to 60 tablets) of her anti-depressant medication, washed down by the rest of the bottle of vodka she had with her.

As she staggered down the street, a married couple and two friends who had been at a 30th birthday party dinner saw her fall over when trying to cross the road and again on the footpath near an ATM.

The group tried to help the teenager and called Triple-0 before Rana drove up in his taxi.

The teenager was unable to say where she lived but the group found her address on a card in her bag.

Judge Wilmoth said one of the group gave Rana $50 to take the teenager home and he keyed her address into the GPS device he had in the taxi.

Rana drove off before stopping the taxi in Camberwell and raping the teenager. He then dropped her home.

The teenager told her mother the next day that she had been sexually assaulted.

Judge Wilmoth said Rana, who came from a middle-class family in Hyderabad and had completed a commerce degree before working for several multinational companies in India, arrived in Australia in 2008 where he completed a diploma course in hospitality and management.

He was driving a taxi to support himself and to save money to return to India.