Everyone would know that there is an exception to the inside lane is the fast lane, outside lane is the slow lane rule. When a sign says "~insert town name~ next 6 exits", the people passing through would stay in the inside lane and go the speed limit (or just a touch more) so that at each of those 6 exits, people needing to leave the highway can and the people merging in can too! I've actually seen a sign that says "through traffic use inside lane" and it made my heart smile.
Why? Cause merging is some serious business, my friend...and it just feels kind to make room. Driving is all about kind, right? Well, it should be. :)