When I’m on the interstate I always find myself moving out of the left lane once clear of slower traffic to my right. I didn’t realize that this happens to be the most efficient way to make use of the left lane. Using the left lane just for passing apparently has some science backing up how efficient it is. It also can reduce the stress of being stuck behind a slow driver sitting the left lane (we all hate that guy don’t we?!). While it has been a law in many states that slower traffic move to the right lane(s), police are now taking a more aggressive approach to enforcement and are starting to ticket drivers who camp out in the left lane. The video below from VOX explains.