Undertaking, aka "Passing on the right" is something I have grown to accept as simply necessary. Hogging the passing lane is not well enforced in America. Germany we are not. Drivers either "don't want to be bothered" with on-ramp traffic, feel that they are policing the speed of the freeway/highway/interstate, or want to diddle away on their mobile phone. Make it quick, do it decisively, and aggressively, and it's fine. My personal record is 11 cars in a line.

But brake-checking? Reckless behavior and is always road-rage. It's not fun or righteous or deserved when someone does it to you for HOURS on the interstate. I've had it happen to me, it's honestly terrifying. It's indicative of the behavior that acts as a red flag for, "Do not Stop, Do Not Pull over, and Do Not Confront another driver exhibiting road rage in the United States...that's how you die [read: get shot]."

If another car is riding your ass, the correct procedure is to let off the gas and coast until you are going so far below the speed limit that they realize what they're doing and back off or pull over and attempt to pass you...where you then resume back up to the speed limit and/or flow of traffic. Problem solved.