We are the only major developed nation that isn't investing meaningfully in high-speed rail, and I believe we're making a mistake. Transportation systems that are fast and efficient and environmentally clean are going to enable the formation of these new mega-regions, the heart of the spatial fix. We need to be able to accelerate the movement of people, goods, and services - the very movement of ideas, knowledge, and creativity - between our major population centers. We have to build these links.