The problem is, at least in more populated areas, there are so many exits that traveling in right-most lane can be dangerous with all of the merging traffic. Large trucks in particular will just cut off cars forcing you to slam on the breaks at least once every mile or two.

The the police should... police that.

Staying out of the passing lane when not passing someone is actually the law in many states. You must keep right if able.

All 50 US states have some type of keep-right law. Whether it's an absolute "keep right unless actively passing" or a looser "keep right when slower than other traffic" varies, but all of them have some kind of enforceable keep-right rule.

All US traffic laws come from the Uniform Vehicle Code. Keep right rules are meant for absolutely slow traffic and not for driving the speed limit. The UVC has keep right exceptions for divided highways with multiple lanes going in one direction.

Passing left laws were intended for two way streets with one lane in each direction when the only way to pass is by driving on the lane going the opposite direction.

> Keep right rules are meant for absolutely slow traffic and not for driving the speed limit.

Do you have a citation for that? Many state laws use the speed of traffic as a reference to define slower as opposed to using the posted speed limit as the reference. If they meant to say only slower than the speed limit, then the text of the law would be explicit on that point.

It's the law here in Colorado. I don't think it's working. People drive in the left lane (when the middle lanes are wide open) all the time.