If you’re just looking at the construction jobs, then who even needs a maglev train? You could get the same economic benefit by excavating landfills and building pyramids out of the materials.
The FR set-up only allows short comments, so I can’t give you the idea all at once. After construction, there’s nominal maintenance, etc. by locals. Have you ever used AutoTrain? They employ a lot of people, from ticketing to car loaders/unloaders.