Over the years I've seen so many car drivers complain about "how long it takes for trucks to pass each other". Well, earlier I was comfortably passing other slower trucks as I was going down the interstate. I started to feel bad that I might be holding up faster vehicles as I was doing that. So, at an appropriate time I got over to let some of them pass. What did they do? They just sheepishly/lazily passed and I lost all momentum. Moral of the story... don't feel guilty. They may feel annoyed for a few minutes, but they aren't looking 15 vehicles ahead the way we do.