Ha, so many people DON'T do these things. I'd add to your "Don't Join In" that you need to allow a little more room in front of you for this to work. Tailgating forces you to hit your brakes when the person in front of you taps theirs.

Just like driving to maximize fuel economy, a lot of these techniques tend to irritate the impatient drivers behind you. People especially hate doing the speed limit (it's an upper limit, right?) or coasting up to a green light that you know is about to turn red.

Although I never do this for the exact reasons you stated, some people do indeed downshift to avoid braking. Let me tell you, it's as surprising as discovering someone's brake lights aren't working. (To be fair, I *have* tried this in my younger days, but found that it was always easier to just hit the dang brakes.)