For clarity on this point, "disengagement" has a specific meaning to the California DMV[0]:
> For the purposes of this section, “disengagement” means a deactivation of the autonomous mode when a failure of the autonomous technology is detected or when the safe operation of the vehicle requires that the autonomous vehicle test driver disengage the autonomous mode and take immediate manual control of the vehicle.
However, some self-driving car manufacturers have been testing the rules quite a lot by choosing which disengagements to report[1]. Waymo reportedly "runs a simulation" to figure out whether to include the disengagement in its report, but there's no mention of what the simulation is or how it might fail in similar ways the technology inside the car did! Thus, the numbers in the reports are likely deflated from being actually every single disengagement.
And even this pathetic and tootheless regulation was enough to drive Uber from California for a while.
With all the games they play with the numbers, Waymo still reports 63 safety-related disengagements for a mere 352,000 miles. This doesn't sound like an acceptable level of safety.
The surprising part is that it appears that Waymo is planning to start deploying their system in 2018. How can they even consider it with this amount of disengagements?
> For the purposes of this section, “disengagement” means a deactivation of the autonomous mode when a failure of the autonomous technology is detected or when the safe operation of the vehicle requires that the autonomous vehicle test driver disengage the autonomous mode and take immediate manual control of the vehicle.
However, some self-driving car manufacturers have been testing the rules quite a lot by choosing which disengagements to report[1]. Waymo reportedly "runs a simulation" to figure out whether to include the disengagement in its report, but there's no mention of what the simulation is or how it might fail in similar ways the technology inside the car did! Thus, the numbers in the reports are likely deflated from being actually every single disengagement.
[0] https://www.dmv.ca.gov/portal/wcm/connect/d48f347b-8815-458e... [1] https://spectrum.ieee.org/cars-that-think/transportation/sel...