A woman has been killed by one of Uber’s self-driving cars.

Uber suspended testing of its autonomous vehicles after the self-driving vehicle struck and killed an Arizona woman over the weekend.

Uber has been testing the vehicles for several months in the Phoenix area, Pittsburgh, San Francisco and Toronto.

The vehicles operate autonomously, but still have an operator behind the wheel.

Uber CEO Dara Khosrowshahi said the company was working with local law enforcement.

Much of the regulation of autonomous vehicles in the US is up to states, with the federal government issuing only a set of voluntary guidelines.

US Transportation Secretary Elaine Chaos says technology and automobile companies need to allay public fears of self-driving vehicles.

Polls have shown that 78 per cent of people fear riding in autonomous vehicles

The state of California requires manufacturers to report any autonomous vehicle incidents to the motor vehicle department. It has received close to 60 such reports so far.

Michael Milford, Chief Investigator for the Australian Centre for Robotic Vision, says it is important not to ignore the value of autonomous cars.

“We know that the self-driving car corporates and start-ups are doing extensive testing to improve the reliability of their cars, which is already very good in many, but not all, situations. We also know that, just as is the case with human drivers, there are occasional pathological situations where it’s near impossible for a car (whether human or autonomously operated) to make a good decision.

“Whether this particular tragic incident is one of those, the fault of the autonomy system, or a mixture of both remains to be seen.”

Dr Zubair Baig, Senior Lecturer in Cyber Security at Edith Cowan University, says the transition to self-driving cars will not be risk-free.

“Autonomous vehicles are here to stay and we must have proper laws in place to safeguard the rights of car accident victims and owners alike. It is imperative to understand that these vehicles are not accident-proof,” he said.

“Dynamics of the surroundings involving unpredictable human behaviour, objects coming off unsecured loads of other vehicles and the ever-present cyber threat to these vehicles would certainly need a serious study by all stakeholders before it's too late.

“Advanced AI can help deter these hazards, provided that the autonomous vehicle is rigorously tested in dynamic road conditions, which seems to be lacking in the current space.”