The hovertrain was a lofty and important step in the right direction, but in practice, the cars are more energy-demanding than initially estimated (via Wired), and in truth, any new rail line would have to be laid with the understanding that the new model would be competing with an existing segment of conventional train access, according to UAS Vision. The economics of these types of building projects are highly complex, but suffice it to say that a newly minted train would certainly cost far more than an established line. Even if the hovertrain could complete a route with high demand in half the time of a competitor, many would likely still opt for the slower train out of financial expedience for years to come.
Another key issue in the rollout of the hovertrain was propulsion. In order to truly hover over a track, the train must be powered by something other than a traditional, and highly mechanically efficient combination of an engine and wheel assembly, this was tackled with linear induction motors, ducted propellers, and other innovations (via Mustard).
Eventually, these designs fell by the wayside. Mustard notes that a combination of technical efficiency — as lower speeds required to turn or pull into a station made hovertrains far less effective than conventional rail transportation — and a global recession led governments around the world to abandon their plans for hovertrain networks.