Looking forward to that one! It looks like a stunning vehicle, and I can't wait to read about your 'test' this Summer.
As to the practicality of it, I don't know.
As for the need for "a whole new road infrastructure to use them", well I don't know; people who buy Porsche Carrera GT, Ferrari Enzo, Lamborghini Gallardo, McLaren F1, etc... don't ask for new roads to use them, do they?