Gosh, I have had just the opposite experience with truckers -- they are professional drivers whose lives and livelihoods depend on caution and skill. Yes, once in a while we encounter a bad apple, usually on the southern Calif freeway system (which is enough to make anyone crazy).
When we do encounter an aggressive trucker, we call the phone number on the door of the truck (or else go to their website) to report them. The dispatchers are almost always appreciative of our comments and they say that they will take action. Who knows if they do? But it is in the company's best interests to weed out the bad guys. So if there are enough complaints about a specific driver, my guess is that they are out of a job.
But I have learned a lot about towing by watching truckers with big semi trailers -- the way they anticipate trouble, the way they drive defensively, keeping a big cushion between themselves and the vehicle ahead, the way they position themselves in advance of an upcoming merge or transition, the way they tap their brakes early to communicate with the vehicles behind them, etc. Very savvy folks, for the most part.
Whenever possible, I slow down to let them move over, giving them a quick flash of my high beams as a signal. It is gratifying when they acknowledge courtesy by turning their lights off/on/off/on, causing their rear lights to blink.