I do not acknowledge posted speed limits. I calculate what speed I think I should be going based on number of lanes, number of intersections, road condition, weather, and my superior driving skills. Usually this works out to be around 20-30mph above the posted limit. There's simply no reason for me to be constrained to the same speed as crackwhores, rednecks, old people, soccer moms, and other bad drivers. My reaction times, vehicle handling, and braking times are all superior to the "average" driver, and I shouldn't have to follow the speed limits that are targetted 2 std devs below the average drivers ability.