TEMPE (Arizona) • Uber has suspended the testing of its self-driving vehicles after one was involved in a collision in Tempe on Friday.

The car, which was in self-driving mode, was not at fault, according to local police department spokesman Josie Montenegro.

The Volvo XC90 sport utility vehicle (SUV) was hit when another driver failed to yield, she said. The collision caused the Uber vehicle to roll over onto its side.

Ms Montenegro and Uber spokesman Chelsea Kohler confirmed the accident on Friday evening, and said neither driver had injuries. "We are continuing to look into this incident, and can confirm we had no back-seat passengers in the vehicle," Ms Kohler said in a statement.

She added on Saturday that Uber was suspending the testing of its self-driving vehicles in Arizona, pending the results of the investigation into the accident.

She said Uber had also suspended testing in Pittsburgh and San Francisco for the day, and possibly longer.

Although Uber was not at fault in the Arizona accident, the incident is problematic for the company.

A start-up based in San Francisco, it has gone head-to-head with regulators in trying to persuade cities to allow public testing of its autonomous vehicles.

Google, General Motors and Ford Motor are all testing autonomous vehicles in California, and have registered to do so.

Automobile companies working on self-driving technology face the difficulty of building smarter vehicles that must not only adhere to the rules of the road but also take into account the error-prone nature of human drivers.

NYTIMES