> We can't keep building new infrastructure (highways) at the pace we did before, because - besides being very expensive - we lack the space for it. New solutio

> We can't keep building new infrastructure (highways) at the pace we did before, because - besides being very expensive - we lack the space for it. New solutions may lie in promoting remote work, carpooling and shortening home/work commute distances. You can build highways and rails in 3 dimensions. The bicycle simply cannot replace cars and trains in any meaningful way, despite the rise in numbers of single, childless urbanites.