The reports, which are mandated under California law and cover October 2014 through November 2015, detail times when the self-driving vehicles “disengaged” from autonomous mode.
- Bosch reported 625 disengagements in 935 miles driven.
- Delphi reported 405 disengagements in 16,662 miles driven.
- Google reported 341 disengagements in 424,331 miles driven.
- Nissan reported 106 disengagements in 1,485 miles driven.
- Mercedes-Benz reported 967 disengagements in 1,337 miles driven.
- Tesla Motors reported zero disengagements and didn’t state how many miles it drove.
- Volkswagen reported 260 disengagements in 14,945 miles driven.
The reports come amid a disagreement among Google, the state’s lieutenant governor and the California Department of Motor Vehicles about how much autonomy vehicles should be allowed to have when they finally transition from the testing phase to public use.
The DMV has proposed regulations that would require a licensed driver to sit behind the wheel at all times, ready to take over at a moment’s notice. That sits at odds with Google’s public plan to make cars that lack even the basic tools necessary for a human to drive it, such as steering wheels. Shortly after the DMV released its draft regulation proposal in December, Google and California Lt. Gov. Gavin Newsom openly criticized the move as one that would hold back autonomous vehicles from their full potential.
Google’s disengagement report, which covers more vehicles and miles driven than any of the others, notes that 272 out of 341 disengagements were related to “a failure of the autonomous technology” — a category that includes broken wires, anomalies coming in from sensor readings, or anomalies in operations like steering and braking. The remaining 69 disengagements were initiated by the driver for safety reasons, but only 13 were in situations where the driver-initiated disengagement prevented the vehicle from coming into contact with another object.
The company stressed in the report that its goal during testing isn’t to minimize disengagements, but rather to learn as much about the AV software’s behavior as possible. That means setting the bar for disengagement high, encouraging the car to hand over control to humans so the engineers can tweak the system based on those moments.
Nonetheless, the Google report noted that the cars have disengaged less often on a per-mile basis as it’s worked on the technology.
“The number of autonomous miles we are driving between immediate manual control disengagements is increasing steadily over time," the report reads. "The rate of this type of disengagement has dropped significantly from 785 miles per disengagement in the fourth quarter of 2014 to 5,318 miles per disengagement in the fourth quarter of 2015.”
But that’s not quite good enough for Consumer Watchdog, a non-profit that’s closely followed the development of AVs in California — especially by Google. Consumer Watchdog Privacy Project Director John Simpson said in a Tuesday press release that the number of disengagements Google has reported only underscores the importance of requiring licensed drivers when such vehicles hit the market.
“The DMV got it exactly right and is putting our safety first,” Simpson said in the statement. “How can Google propose a car with no steering wheel, brakes or driver when its own tests show that over 15 months the robot technology failed and handed control to the driver 272 times and a test driver felt compelled to intervene 69 times?”
