In the next decade, Florida’s biggest cities will add toll lanes to the state’s busiest highways. Nobody knows exactly how much it will cost. Maybe as little as $3 billion. Maybe double that. What’s clear is that when the toll lanes across the state are complete, they will become one of the largest infrastructure projects in state history. There’s little debate that the toll lanes, also called express lanes or managed lanes, make commutes quicker for those willing to pay as much as $10 to use them. But there has been little debate about the need for the projects —...