In the U.S. alone, there's more than four million miles of roads, very expensive to build, very expensive to maintain infrastructure, with a huge ecological footprint, and yet, very often, congested.
仅在美国，就有超过400万 英里的公路，建设成本极高， 基础设施维修保养费用极其昂贵， 并留下巨大的生态足迹， 但同时，经常非常堵塞。