[Robotbeat]

I don't think it's silly at all, although there are probably other ways to do it (license plates are a known size, so they could be used for calibration... to some extent). In fact, I think going to a sort of mapping solution where some portion of the Teslas on the road provide mapping data (using just calibrated vision) may be appropriate. If the reason you aren't using maps as an extra layer of capability is just because of the cost of mapping, then using Teslas to provide mapping capability "for free" is a good solution.

The argument may be that humans do fine without mapping, but that's not strictly true. Humans remember and anticipate the road based on past memory. When there's a change in the road due to construction, there's often a sign placed to warn drivers of the change in traffic pattern, showing that humans definitely at least partially rely on "mapping," so it could help even a pure vision system.