Circles and squares in squares. What could be simpler? Almost anything. Today, it’s the old toll booths on the Mass Turnpike. They’ve been removed now and they check your entries and exits using cameras and signals. But before that and for years and years, we had toll booths. I have no idea how people who don’t have a tag on their car pay for using the pike. I know they do it, so I assume they photograph the car’s license plate and bill its owners. Something like that!