Please see my edit in my original post to clarify what I meant to write. In fact my speed ranges up and down based on the level of congestion, whereas the safe buffer I maintain in front of me remains constant - and by safe I mean long enough that I don't have to use my brakes when traffic slows.
As for my use of "zen", don't read too much into it. It was just a tongue-in-cheek reference to the fact that I stopped trying to fight the flow of traffic and instead simply pass through it as peacefully as possible.
>That's heavily dependent on time and place.
My observations are limited to highways in Ontario, Quebec, New York State, Pennsylvania, and Massachusetts.
>I only get annoyed with such people when they try to keep other people from filling that gap
Hey, man, you're welcome to it. Blocking another driver from filling the gap would mean accelerating to close it, which kind of defeats the purpose of maintaining it.