[crusty old prospector]

Yes, they are power rings.

[spokeshave]

why not driverless big rigs hauling freight all over the country.

Because road conditions change frequently,,,and where does the AI get informed when the truck goes in a tunnel...not to mention variable "black ice" conditions.

AI may be Artificial but is not Intelligent.

How is it going to drive a big rig with 7 speed manual transmission and high/low gearbox settings,,,?

Spokeshave who was a big rig driver in a previous existence.