Not on a commute, but this thread seems appropriate.
Two of us out on a road ride near Langholm. We're riding abreast having a chat while climbing and I popped a look over my shoulder. A truck had just come round the last corner, at least 400 metres away, so I put a spurt on to get ahead so we could single out.
Honk!
He was still 300 yards back when he did that, just as I accelerated. He did that to make sure we knew he was there.
We went round the next corner in single file and the truck passed nice and wide as we came out of it, and got a thankyou wave.
Really enjoyed that ride