Broadly speaking, there are two different entities called Managed Lanes (ML) in the U.S. transportation these days. One of them consists of an HOV lane whose operator has decided to sell its excess capacity to willing customers, using variable pricing. In this column, I’ll refer to these as HOT lanes. The other consists of new lanes whose developer/operator aims to sell faster and more reliable travel to willing customers—and may or may not allow certain kinds of HOVs to operate either free or at a reduced toll rate. I’ll refer to these as Express Toll Lanes. Many elected officials don’t really understand the difference between the two kinds of ML, but they are profound.