Since when is 55 the new 45???

I started a full time job and every morning I make the 40 minute commute. There is a stretch of land that I drive through that is farmland. The speed limit is 55mph which, of course, means 60mph. Every morning I get behind someone who will not go over 45mph. There are no cars in front of them and I get thoroughly frustrated with these people. I may tailgate a little bit but not too often because there are those who also feel the need to not only go under the speed limit, but also brake for absolutely no reason. I may have to revert the horn. I got out of the horn habit when I moved to Oregon because no one seems to honk here. I have my time planned out on the way to work, where I need to be and by what time but these morons who can't drive are all messing it up for me. They should have a moron, can't drive lane and a lane for expert drivers.