Following an incident in which a woman was killed by one of Uber’s autonomous vehicles in Tempe, Arizona on Sunday, the city’s police chief has said that it’s unlikely the car was at fault.

The victim, 49-year-old Elaine Herzberg, was reportedly hit by the vehicle when it was travelling 38mph in a 35mph zone. According to early police investigations, she suddenly stepped into the road pushing a bicycle and the car, which was in self-driving mode, made no attempt to brake.

“It’s very clear it would have been difficult to avoid this collision in any kind of mode based on how she came from the shadows right into the roadway,” Tempe police chief Sylvia Moir told the San Francisco Chronicle.

“The driver said it was like a flash, the person walked out in front of them…His first alert to the collision was the sound of the collision.”

According to the police department, the incident happened in a poorly lit area, less than 100 metres away from a pedestrian crossing. “It is dangerous to cross roadways in the evening hour when well-illuminated, managed crosswalks are available,” Moir added.

In the 3 million autonomous miles Uber’s driverless fleet has racked up, this is apparently only the second time one of the cars has been involved in a road traffic incident. In the previous collision, in which an Uber vehicle ended up on its side, the driver of the other vehicle involved was found to be responsible.