the right lane should be cruising. Should you need to pass someone here you move over one left lane. If you find youself needing to pass someone in this lane, you should move over again to the left lane. If you find someone here going slower than you, they really are supposed to move over. You shouldn't be cruising in the left lanes at all ever unless passing. Drivers ed never enforced this rule over here, which astonished me. But in the UK, where they deal with worse traffic congestion, you get pulled over if you don't follow this rule. Not to mention passing on the right is forbidden. If most americans would follow this rule the roads would flow so much better.