Later this year, Barack Obama's transportation secretary Ray LaHood will begin allocating $8 billion to emerging American train systems, with another $5 billion to come over the next five years - the first time ever that the US government has made such an investment. Until this year, the idea that Americans could enjoy European or Japanese-style train service was dismissed as a boutique cause of cosmopolitan columnists and futurist dreamers. Now leaving the country a set of rails equal to its roads will be Obama's transport legacy. Monocle's Washington Correspondent Sasha Issenberg travelled with LaHood on European reconnaissance mission.