- 2014 (last 3 months): 1.27 [1]
- 2015: 0.80 [2]
- 2016: 0.20 [2]
- 2017: 0.18 [3]
There are two possible causes off the top of my mind:
1. Waymo's cars are being tested in more demanding environments.
2. There's a floor to the number of disengagements due to technology and road conditions: situations that are different/unique enough that no model could accurately detect/respond to it.
Case 2 would be definitely be a problem for the full-autonomous (i.e. zero user-input) type of car. I'd love to hear other hypotheses/feedback from those closer to this kind of work!
Also, another interesting note: total miles driven on public roads is actually down from 2016 (352k vs. 636k earlier). Perhaps Waymo's finding the simulated/private-road tests more fruitful for winnowing down the final edge cases.
[1] https://www.dmv.ca.gov/portal/wcm/connect/dff67186-70dd-4042...
[2] https://www.dmv.ca.gov/portal/wcm/connect/946b3502-c959-4e3b...
[3] https://www.dmv.ca.gov/portal/wcm/connect/42aff875-7ab1-4115...