I think the concept is good of small areas all walkable or reachable by train, but the concept would be much more workable as a circle with spokes, with “green” or shared public spaces in between.
A spoked circle would cut the travel time needed to go from one area to another remote area, either partway around, or up one spoke to the center and then to another point on the clock face, or straight across and partway around. As it is, traveling from one end to the other would take maximum time. This would present challenges for distribution of goods and services.
Unless, of course, they intend to corrall people into the so-called “15-minute” segments that are barricaded from one another, each with individual power plants and supply centers replenished by drone. Since the “line” map shows it going inland instead of parallel to the shoreline, they could not use boats for efficient distribution to the far end.
Are they going to rumble trucks or container trains down the one main thoroughfare? If the train tracks bisect the city like a spine, wouldn’t they soon have social divisions from people “on the wrong side of the tracks”? Will they have high pedestrian bridges, or will pedestrian or train tunnels have to be underground, in the shifting sands of the desert? Many engineering challenges.
“The Line” would also be a lot harder to police than a circle, IMHO. Which of course they will want to do. A straight line would put maximum stress on power plants, and would make the entire city more vulnerable in case of attack, as well.
You are correct