[Q] No respect and bad road manner from other driver?

The difference between 55 and 75 mph is "only" 20mph, how did you not see that you're catching up to a slower vehicle with plenty of time to plan ahead? Did it just magically appear over that hill? Or did you have a chance to see it climbing the hill slowly in front of you?

Here in MA, there's a lot of hills steep enough that heavy trucks have trouble doing more than about 40mph up them. The left lane is usually full of BMWs going 80. That's a 40 mph speed difference in somewhat heavy traffic, and yet this stretch of road that I drive every day isn't littered with accidents.

 

Regarding speed difference between lanes: the time I sense the most danger is when the left lane is bogged down, I'm in the right lane and moving ok. You know by their dna some left laners are going to be itching to jump lanes. I'll slow down, cover the brake/horn. I don't much care if they "cut me off", just want to get through in one piece.

 

and then there are the people who stay in the left lane until they reach their exit, and suddenly cut acrost three lanes of traffic.