See this all the time. one hundred plus miles one way to Dr and over on hundred round trip to stores. i avid the Interstates as much as possible. Wife drives when we are together and hitting the brakes every little bit to avid collision with Semis who out number cars and run whatever speed they want in left lane. it is proper etiquite to flash your lights at vehicle in front of you impeding traffic whatever the speed and the law for slower vehicles to stay right. In Oklahoma they have signs both sides of the lanes and the left one says illegal to impeed faster traffic, or some such. They enforce it. In Tn. and other states no signs and the Truckers Associations are in control.
A lot of towables on the road being delivered to lots and many now pulled by SUVs we observed.Flas your lights and like as not they will slow down and give you the finger. In Az n I40 we observe many riding the left lane at slower speeds obstructing traffic...but the road is really bad from outside Kingman in sections to Flagstaff.
cars semis RVs see many same offenses . I drive 55 and don't care about anyone else on the road is read frequently in different words. Doesn't matter if it is the right lane, It will case ht semis and others to get in the left and pass you at just 10mph faster if that.Backups can run for 20 miles in Tn can run over 20 miles due to these games and attitudes, and causea lot of wrecks and angry divers.