People should drive so as to not impede others, that's more courteous than driving at a speed YOU want that impedes others.
That encompasses a lot of behaviors.
The point is that nobody should need to maneuver around you.
Similarly, I believe in merging at a speed a bit above the traffic, which allows the option of slowing to fit in, or finding a gap to fit into.
That also sends the message that you're not going to impede flow.

I prefer the style of left-most lane for speed, right lane for access/egress.
Long ago I developed a habit of quick analysis of who's around & ahead of me to avoid possible issues.
On interstates or freeways, I generally place my vehicle so I'm not at the mercy of others.
Generally my goal is to be in the biggest gap.
That works: I've avoided wrecks around & ahead of me and all manner of foolishness.
You can do all that and travel courteously at a pretty good clip if you're paying attention.