I saw a blue peterbuilt tractor drive down Charleston (in Palo Alto) this afternoon that had a bar mounted on the cab with what seemed to be 5 or 6 cameras. No trailer. Older model truck...or a retro model? (I don't know semis) It's definitely not like the white Google tractor I've seen in the shoreline parking lot--that one has sensors much more like the old lexuses... Tesla? Some other random startup?