It is law in Indiana that the left lane is for passing and not for driving. You can be ticketed for this. In fact, Indiana State Trooper Sergeant Todd Ringle reminded folks of that in a tweet about the upcoming holiday weekend:

 

Sergeant Ringle later tweeted about a woman that he had just pulled over for doing exactly that:

 

 

The bottom line, as Sergeant Ringle pointed out is: Stay right except to pass! A lot of folks will be out traveling this weekend. Be safe out there!