[Someone]

"their reasoning that they must ignore stationary objects to avoid too many false positives sounds pretty reasonable to me"

I don't understand your logic. Stationary objects either are rare, and wouldn't trigger too many false positives, or they aren't, and the car should be prepared for them.

[oxygen0211]

"Stationary objects either are rare"

I think the problem with this is to set them into the correct context. Around the road (and thus in the visible field of the sensors) you have A LOT of stationary objects such as houses, trees, traffic signs, roadside objects, parked cars, ... I think there is probably a big challenge determining which of these objects might be in the way and how to correctly ract to them.

Just as an example: Considering the situation the article and enhancing it a bit with guessings, it would have been the right decision to either stop or change lanes (depending on the road). However, if the car decides to change lanes and there is traffic on the other lane, we are in the same trouble of an accident due to autopilot again. Also, if autopilot decides to change lanes (or something similar in the category of "driving around") on a one-lane road (maybe even with missing lane marks), we might end up in oncoming traffic. Or what happens if the system falsely applies the decision to break in a turn with roadside objects (think of a 90° turn with a house in the corner). If the car falsely applies an emergency break here, our hypothetical car might be the one smashed into. Also, how do you set the thresholds for "stationary". If it is set too low, we might not stop infront of a stationary object until it is too late, if we set it too hight, we might stop way too early, say, in a traffic jam, again being the ones provoking accidents or more traffic jam due to unforseen heavy breaking.

[Someone]

Yes, the problem is difficult and hasn't been solved yet. Knowing that, Tesla should have figured out how to safely disengage autopilot and transfer control back to the driver before selling this feature (an autopilot in a plane, for example, can alert the humans in the cockpit way in advance of upcoming problems, and has incredibly annoying ways to get their attention, if needed)

I saw a tv program about self-driving cars a couple of years ago where the programmers said they would have it ready for major roads in a couple of years, but their human factors engineer said "a couple of decades", precisely because they realised humans would always be needed, and that the problem of transferring control back to humans while riding on the road hadn't been solved.

[alex_stoddard]

I'm inferring from the article the problem is spatial/temporal resolution of the _radar_ currently being used for speed sensing for adaptive cruise control. There are lots of objects that are stationary and near to the road but not in the path of the vehicle (road signs, overhead signs).