I always try to do the "average speed" thing in stop and go traffic (if for no other reason that I have a manual transmission and it's really annoying to have t

I always try to do the "average speed" thing in stop and go traffic (if for no other reason that I have a manual transmission and it's really annoying to have to stop and start...) and it has another effect that this page did not mention. The spaces that open up in front of you can often be quite large, and a substantial fraction of the drivers behind you (who presumably have not learned about travelling waves) will honk, flash their light, or even cut into the other lane, pass, cut back in front of you, speed up to 60mph and then slam to a stop, just because you are obviously "not keeping up with traffic".