Amtrak’s route from Chicago to St. Louis would seem an ideal place for the U.S. to adopt high-speed rail such as in Europe and Asia, where passenger trains can race along at 200 miles an hour. The stretch in Illinois is a straight shot across mostly flat terrain.
In fact, a fast-rail project is under way in Illinois. Yet the trains will top out at 110 mph, shaving just an hour from what is now a 5½-hour train trip.
After...