We were driving across Nevada a week ago when it began snowing moderately east of Winnemucca. I had TACC on, but I had dropped Autosteer since lane line visibility was getting sketchy. All was performing flawlessly when I suddenly got a message (from memory, so not word-for-word) saying, "Autopilot features disabled. Radar visibility lost." My first thought was that I had to get the car fixed. My second thought was wondering whether ice was accumulating from the car ramming its way through snowfall. Sure enough, when we got to our next Supercharger in Elko, there was a centimeter of ice on the front bumper. I knocked it off gently, and full EAP features magically returned for the rest of our trip. And, yes, the manual says TACC may cancel when "The view from the radar sensor or
camera(s) is obstructed. This could be caused by dirt, mud, ice, snow, fog, etc." This was the first experience of this for this Sacramento boy, though I bet those of you who live in snowy places have seen this many times.
So now let's step into the time machine. It's some years from now, and Full Self-Driving is an actual thing, with whatever hardware and software upgrades, regulatory approval, and whatever else is needed. (This is a fantasy, so go with it. I'm not trying to start a debate about whether or when we'll ever see FSD.) We have FSD engaged. It's Level 5, so no more steering wheel nags. In fact, as we engaged FSD, the screen displayed a pleasant message: "I got this. Enjoy your nap." And as it's driving along while we snooze, it loses its radar, just like happened to us last Friday. Then what? Loud noises to wake up the driver? Last week I was fully engaged when EAP shut down, so it was no panic, no problem. But if the driver is inattentive when FSD can't do it anymore, then what? SAE Level 5 says, "The vehicle is capable of performing all driving functions under all conditions." Level 4 says, "...under certain conditions." Is it Level 5 that's the fantasy? Is 4 the best we can ever really hope for, if the car's sensory input is subject to impairment by weather, which would clearly fall within "under all conditions"?
PS: We just bought the $2K FSD upgrade...