The experience will be no different from riding in an airplane with the shades drawn, and technical issues around maintaining the vacuum within the tube will be solved, he believes.

Instead, hyperloop projects will face more mundane challenges.

“Getting innovative things through the regulatory and certification environments is very difficult,” Mr. Reisman said. “This could face an uphill battle in the U.S.”

Which companies will succeed, if any, is anyone’s guess. Yet each main player is rooting for the others, knowing that one failure will put a pall over the technology as a whole.

“The worst thing that would happen to us is if Virgin Hyperloop One is not successful,” Mr. Ahlborn said.

Whether any company can garner the necessary finance is still an open question, leading Mr. Ahlborn to wonder if any one can ultimately go it alone. “Maybe there could be a consolidation between our companies,” he said.

Rick Geddes, professor in the department of policy analysis and management at Cornell University , sees a different challenge. “The biggest problems for hyperloop will be securing rights of way and permitting,” he said.

Still, Professor Geddes believes that hyperloop systems will become a reality, as the time is ripe.

“There’s a sense that things are stale; we’re just adding to existing modes of transport,” he said. “Time is more and more a valuable commodity. The transportation industry is ready for a new way of thinking.”