Comment by JBlue42

>Though I suppose an investigation into the matter would arguably have to look at whether a competent human driver would be driving at 17mph (27km/h) under those circumstances to begin with, rather than just comparing the relative reaction speeds, taking the hazardous situation for granted.

Sure but also throw in whether that driver is staring at their phone, distracting by something else, etc. I have been a skeptic of all this stuff for a while but riding in a Waymo in heavy fog changed my mind when questioning how well I or another driver would've done at that time of day and with those conditions.