Around here (other places too, I suspect), the highway department is adding toll-charge Express Lanes that run side by side with the main (free) lanes on major highways. I'm not sure whether the highway department itself is doing it, or whether the state authorities have licensed the project to private companies that install the new lanes & take the toll money. Regardless, the express lane tolls are collected only via E-Z Pass (or the equivalent) -- no toll booths, no coin bins, no charge card slots, just dedicated toll transponders.
The Maryland Chesapeake Bay Bridge, which carries U.S. Rts. 50 & 301 between Maryland's Eastern Shore & the rest of Maryland, got rid of all its toll booths & replaced those with transponder readers on the eastern side. There are highway signs saying E-Z Pass Only, but nothing about toll by plate, etc. It's hard to believe there's no provision for paying the toll other than E-Z Pass. If that were the case, every vehicle without E-Z Pass would be a toll violator.
The way things are going, it can't be much longer before there are smartphone apps for paying highway & bridge & tunnel tolls. Won't that be something ?
-- Alan Cole, McLean (Fairfax County), Virginia, USA.