America’s highway system, once a symbol of freedom and mobility envied the world over, is crumbling physically and financially, the potentially disastrous consequence of a politically driven road-building binge. President Barack Obama, state transportation officials, civil engineers, road builders and business groups all say that the country needs to invest trillions of dollars in its infrastructure, yet there’s little consensus on how to finance it or what the most pressing needs are. The Congressional Budget Office estimates that the country needs $14 billion in additional federal funds each year just to maintain highways and $50 billion more to improve them....