Video of a deadly self-driving vehicle crash in the US shows a pedestrian walking from a darkened area onto a street just moments before an Uber SUV strikes her.

The lights on the SUV didn't illuminate 49-year-old Elaine Herzberg on Sunday night until a second or two before impact, raising questions about whether the vehicle could have stopped in time.

The crash on Sunday night in Tempe in Arizona was the first death involving a full autonomous test vehicle. The Volvo was in self-driving mode with a human backup driver at the wheel when it struck Herzberg, police said.

The video shows the human backup driver in the SUV looking down until seconds before the crash. The driver looks up and appears startled during the last moment of the clip.

Tempe Police Chief Sylvia Moir has told the San Francisco Chronicle that the SUV likely wouldn't be found at fault.

But experts who viewed the video said the SUV's laser and radar sensors should have spotted Herzberg and her bicycle in time to brake.