Stop me before I merge again

AMERICA'S railways were once the envy of the world, the transport backbone of a scorching economy and the stuff of legend. But over the past few years they have also become a mess so embarrassing that in March their regulator took the unprecedented step of banning all further mergers until they can sort themselves out. Worse, it did so at the request of most of the rail firms themselves, a telling reflection of a once-great industry that has in recent years become its own worst enemy.