FSD does have a merge right rule, but it can be turned off. The sort of person who'd do what you describe sounds like someone that would turn it off too. :facep

FSD does have a merge right rule, but it can be turned off. The sort of person who'd do what you describe sounds like someone that would turn it off too. :facepalm Of course, it could also have been one of the cases where the car just navigated poorly and thinks it needs to be in the left lane for some reason. The vehicle's lane selection is not great, IMO.