The left lane is the passing lane, not the camping lane. Camping is to be done in approved campsites, which are never on the highway. If you are driving your vehicle, keep right, pass left.
You can't imagine how many times I was stuck in traffic for no reason other than some
But that was the one lucky time. Too often, there was a line of 30 cars in the left lane, and one good citizen going slow where he belongs -- in the right lane. No way past. Hello traffic for the next 10 miles.