I always use cruise control on country driving, which I do every week. 110 km/hr, spot on by the GPS, or 100 if the limit is 100.
I cruise up behind someone from miles back and so pull out to pass.
As I draw level, they speed up to exactly match my speed. Why ???

Or,.. I'm cruising down the highway at 110 on cruise control, and someone comes roaring up behind me from miles back, pulls out and passes me,.. then cuts in really close,.. and then slows down to 105. Why???

Or,.. I'm cruising down the highway at 110 on cruise control, and someone comes roaring up behind me from miles back, pulls out and passes me,.. then cuts in 2 car lengths in front, and then slows down to exactly 110 and sits there 2 car lengths in front. Why???

I agree, WA drivers are some of the most rude and inconsiderate drivers on the planet.