Google’s self-driving car hit a public bus on a busy street last month in the company’s hometown of Mountain View, Calif. — perhaps the first incident of its smart cars causing an accident while in autonomous mode.
The Associated Press reported that one of Google’s self-driving Lexus SUV vehicles struck the side of a bus on Valentine’s Day. Google’s autonomous cars have been in other accidents before, but all were the fault of human drivers — at least, until now.
No one was injured in the accident because the crash occurred at low speeds, Google said in a report filed with the California Department of Motor Vehicles, though the left side of the Google smart car and its driver-side sensor suffered damage.
In a statement, Google said it bears “some responsibility” for the crash. The company noted that both the car’s software and its human test driver believed that the bus was going to allow them to merge back into the center of a wide lane on El Camino Real Boulevard, in order to avoid some sandbags that were obstructing the rightmost part of the lane. The bus did not yield, and the self-driving car crashed into the bus.
To prevent future crashes, Google engineers have reprogrammed the smart cars to understand that larger vehicles, such as buses, may not be as inclined to yield as other vehicles.
In recent months, Google has been teaching its self-driving cars to hug the right side of wide lanes when it wants to turn right to allow other drivers to pass, rather than obstructing traffic and making other drivers impatient as Google’s car waits to turn. This software tweak was part of the reason for the accident because the Google car was driving on the far right side of the lane when it encountered the obstruction and had to move back toward the center, where it subsequently hit the bus that had been behind it.
“It’s vital for us to develop advanced skills that respect not just the letter of the traffic code but the spirit of the road,” Google said in the report. “This is a classic example of the negotiation that’s a normal part of driving — we’re all trying to predict each other’s movements.”
Since it started driving on city streets in 2014, Google cars have been involved in nearly a dozen minor collisions that caused no injury to any party in or around Mountain View. In most cases, Google’s cars were rear-ended.
The U.S. Department of Transportation’s National Highway Traffic Safety Administration reports that human error causes most accidents. This means that automated cars could save up to 300,000 lives per decade in the United States and could reduce accidents by 90 percent because smart cars — when the software works correctly — are not accident-prone.
Google has been expanding its smart car test driving program and most recently began tests in Kirkland, Wash. in January. Kirkland is home to an existing Google campus that just expanded and the company wanted to test its vehicle with hills, variable temperatures, and different weather conditions — in particular, rain that will help the self-driving cars learn to deal with wet roads.
Last week, the U.S. National Highway Traffic Safety Administration told Google it would likely give the self-driving computer the same legal treatment as a human driver. However, this collision may be a setback for Google’s plans with its self-driving cars — especially the vehicles without steering controls that Google eventually hopes to test on public roads.