The South Australian Opposition wants an overhaul of Adelaide's taxi industry, amid two new reports of sexual assaults by drivers.

Opposition transport spokesman Martin Hamilton-Smith says it is alarming that there have been nearly 30 attacks on women in taxis in recent times.

He says four things must happen immediately.

"Deliver better GPS satellite technology to cabs, improve in-cab cameras, better training and more inspectors," he said.

He says Premier Mike Rann is wholly responsible for the troubled industry and has failed to meet promises made since forming the Premier's Taxi Council five years ago.

The Australian Taxi Conference will be held in Adelaide from Sunday.