I would love to see a city like this built today, but with a little less emphasis on experimental and more on starting with the best practices we know today, and designing for a large scale from the outset like China does.
Things like being designed around pervasive rail-based mass transit, and that being cheaper to build when you don't have to put it in an existing city. Pedestrian optimized streets with much less parking than today's cities. Little-to-no single family zoning, replaced with missing-middle apartment and mixed used neighborhoods. Large parks. Plazas and outdoor dining. Buried utilities. Either rooftop solar, or green roofs everywhere. Modern underground trash collection. Cut-and-cover highway tunnels.
There's a lot of space in Montana, Wyoming, the Dakaotas, and we'll need more space for population there as we have to migrate north.
There's a lot of space in Montana, Wyoming, the Dakaotas, and we'll need more space for population there as we have to migrate north.