If you're being tailgated doing the speed limit or a few over, you will be tailgated at any speed. Many times, I've driven at 10 over, passing the cars in the inside lanes, and had completely irate drivers right on my bumper. I think their issue is that I should be tailgating the folks in front of me. Because I won't, they go nuts. When they get past me, they immediately speed up to catch the faster vehicles and begin tailgating them.
When traveling, I do 62 on fast roads and 55 when that's the speed limit. If possible, I'll move aside if it's safe. Always in the right lane on roads with 2 lanes in my direction.