The concerns were raised after a driver was bashed and robbed on Saturday night after collecting customers from outside John Wickliffe House, in Princes St.
The City Taxis driver spent the night in Dunedin Hospital after he was assaulted by one of the two passengers he drove to Kettle Park, on Moana Rua Rd, about 11.20pm.
Detective Sergeant Chris Henderson said one of the passengers, a "thin, stringy" European man, got out of the taxi's back seat as soon as the car stopped on the St Kilda street.
The woman in the front passenger seat then allegedly turned on the driver, punching him in the head and taking his fare money.
She fled across the Kettle Park playing fields and on to Victoria Rd.
The driver called for help and was taken by ambulance to Dunedin Hospital.
He had cuts on his face and stayed in hospital overnight, Det Sgt Henderson said.
The attack came "out of the blue".
There was no verbal abuse and no indication the woman, a small, pony-tailed, dark-haired Maori or Polynesian woman in her late teens or early 20s, was poised to attack, he said.
Det Sgt Henderson confirmed police could not rule out the possibility the attack was planned before the cab was hailed.
He said police wanted to hear from anyone who saw the pair walking from the Rattray St corner to the taxi stand, or who saw them running from Moana Rua Rd.
The scene was cordoned off yesterday and the taxi was later taken away for a forensic examination.
Another car parked beside the taxi was also examined.
The driver declined an interview and City Taxis manager Frank Wilks did not return calls.
When contacted, Dunedin driver and New Zealand Taxi Federation executive member Bill Collie said such assaults were very rare in Dunedin - "which is still a pretty good place to work" - but some drivers, including himself, did not think Friday and Saturday fares were worth the trouble caused by drunks and petty criminals.
People needed to understand the testing environment in which drivers worked, but Mr Collie was worried further publicity would encourage "copycats".
Government plans to make in-cab video cameras compulsory would provide another level of protection for night-shift drivers - but he hoped they would seldom be needed to identify violent criminals.
