"그는 등을 긁어요."
Translation:He scratches his back.
Nice sentence but I honestly can't see its relation to the topic traffic
Indeed how out of blue! lol
He scratches his back while waiting for his bus. =버스를 기다리는 동안 그는 등을 긁어요. "
I'm guessing it's to introduce words used elsewhere in the topic in different contexts so it helps you learn them more easily.