SAN FRANCISCO -- Four experimental self-driving cars have had fender-benders on California roads since September, when the state first required companies such as Google Inc. to hold permits for testing on public roads, according to a new report.
Three of the four crashes, which were first disclosed Monday by the Associated Press, involved the Lexus RX450h crossovers that Google uses to test autonomous driving technology. One involved an Audi crossover owned by supplier Delphi Automotive.
Both companies told Automotive News that their self-driving cars, which use sensors, maps and software algorithms to pilot themselves on public roads, were not at fault.
Yet the crashes show that self-driving cars cannot avoid all accidents. Google said its Lexus fleet has now driven almost 1 million miles in autonomous mode without causing a crash, but a few minor dings in traffic are still inevitable.
“Even when our software and sensors can detect a sticky situation and take action earlier and faster than an alert human driver, sometimes we won’t be able to overcome the realities of speed and distance,” Chris Urmson, the head of Google’s self-driving cars project, wrote in an article posted Monday on Medium.com.
Google, the Internet giant, has spurred intense public interest in self-driving cars since it started testing them six years ago on the streets and highways around its Silicon Valley headquarters. Its fleet of cars, which have a trained driver at the wheel in case something goes awry, now travel 10,000 miles per week in self-driving mode.
‘Crazy experiences’
Google’s response to the AP report illustrates a major challenge facing the Silicon Valley technology giant as it races suppliers such as Delphi and Bosch and automakers such as Audi, Mercedes-Benz and Nissan to develop self-driving cars.
Self-driving cars are seen as potentially safer than human drivers, as they do not drive drunk, fall asleep or fiddle with smartphones as human drivers do.
Yet it may not be enough to be safer than humans. Computer-controlled cars may need to be nearly perfect for an easily spooked public to accept them.
Google says its cars have been involved in 11 accidents over six years without an injury.
They have been hit from behind seven times, Urmson wrote in Monday’s article, side-swiped twice and “hit by a car rolling through a stop sign.” These accidents were spread across 1.7 million miles, including 700,000 miles driven under human control.
Regulators may be tempted to scrutinize that data point -- one crash per 154,545 miles -- to assess the safety of today’s self-driving cars.
Google warned it is difficult to compare its accident rate to the national average because many fender-benders are not reported to police. The company said continuing to test its cars on public roads is crucial to its mission.
“All the crazy experiences we’ve had on the road have been really valuable for our project,” Urmson wrote. “We have a detailed review process and try to learn something from each incident, even if it hasn’t been our fault.”
Privacy group hits Google
The exact circumstances of Google’s crashes remain unclear.
Two of the four crashes reported to the California Department of Motor Vehicles since September took place with cars in self-driving mode, according to the AP report. The other two occurred while the cars were under human control.
By policy, the California DMV does not disclose the details of accidents involving self-driving cars. Google would not share details on its crashes, including the date, location and specific circumstances under which they occurred.
That prompted a complaint from the California advocacy group Consumer Watchdog, which says the public should know about the safety record of self-driving cars. John Simpson, director of the group's privacy project and a frequent Google critic, said it is ironic for Google, whose mission statement is to “organize the world’s information and make it universally accessible,” to keep its accident records secret.
“Google has engaged in a highly visible public relations campaign extolling the supposed virtues of driverless cars,” Simpson wrote in an open letter to Google CEO Larry Page and Chairman Eric Schmidt. “It is incumbent upon you to be candid about the cars’ failings and shortcomings as well.”
Delphi’s police report
Delphi, which is working on self-driving cars to license the technology to automakers, confirmed that one of its test cars was involved in an accident last fall. Kristen Kinley, a Delphi spokeswoman, said no one was injured in the crash.
“While operating in manual mode and stopped at an intersection, our car was struck by another vehicle that traveled across the median,” she wrote in an email. “A police report indicates the fault of the accident is with the second vehicle. Not Delphi.”
A copy of the police report provided to Automotive News shows that the accident occurred on Oct 14 in Palo Alto, Calif., about half a mile from Delphi’s Silicon Valley r&d center in Mountain View, Calif., and 1 mile from Google’s headquarters.
The report says Delphi’s test vehicle, a black Audi SQ5, was stopped in a left-turn lane when it was broadsided by a silver Honda Civic that crossed the concrete median. The police officer who filed the report concluded that the Civic’s driver was at fault.
Delphi’s testing has moved forward since then.
In late March, ahead of the New York auto show, Delphi took a self-driving SQ5 on a cross-country road trip from Mountain View to Manhattan. The car completed the journey without any major problems.
“We observed that our vehicle is a bit skittish around semi trucks,” Kinley said. “We also were passed by lots of unhappy drivers,” she added, “because our car always obeys the speed limit and is extra cautious.”
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