Why a Raspberry Pi Can't Be a Stoplight [video]

It's a clickbait title (aren't they all?), but the premise is weird too -- because I don't see anything preventing the use of a RaspPi -- the offhand remark is that their has to be "redundancy"... but I'm going to guess you could build something a bit more redundant with a Pi if you wanted?

The video is interesting (and the main guy does lots of cool road vids), but the Pi thing is just odd.