Why even worry about this? I routinely drive 5-15 mph above the speed limit and I have yet to get a ticket because there is absolutely no shortage of ticket-magnets who will drive 25 mph over the speed limit while zigzagging between other cars, somehow forgetting that they're the ones always getting the tickets (either for speeding or reckless endangerment).
In a few states that do ticket for going too slow, they tend to also have the stipulation that you didn't keep to the right. At which point I have no sympathy for them, because driving slowly in the left lane when you have no reason to (to my knowledge there is only one freeway here that has a left lane off-ramp/merge) is really annoying.
http://www.theblaze.com/wp-content/u...AM-620x300.png