AECOM (No. 1) disrupted size norms in the design world in 2014, when it purchased URS Corp. By the end of last year, it had became an $18-billion engineer-construct behemoth with more than 90,000 staffers.

The firm now is building on broadened capabilities to cast its lot with mega-disruptor Elon Musk, CEO of Space-X, and other technology firms to build U.S. test beds to assess the viability of the ultra-high-tech Hyperloop transportation system that the developers contend could one day could move people and goods in levitating pods through vacuum tubes at up to 750 miles per hour.

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The business arrangements of the Hyperloop builders are as new-wave as their technology, and details on their staffing, activities, project costs and contracting are shrouded in secrecy.

Hyperloop Transportation Technologies Inc. (HTT)—an independent Space-X technology developer with which AECOM announced an arrangement last year to build a test track in Quay Valley, Calif.—says its project development firms and staffers work part-time in exchange for stock in the company while keeping their day jobs.

But AECOM played down that stock link in media coverage of its contract announced in January to build a five-mile test track for Space- X near its Hawthorne, Calif., base. The engineer also is believed to be part of test-track development, near Las Vegas, for yet another Hyperloop startup, Hyperloop Technologies Inc..

AECOM in January told The Verge, a technology publication, that it “has not endorsed or validated any technology or approach."

An AECOM spokesman says the churning pace and clients’ secrecy in Hyperloop work have kept details on test-track progress and technology sporadic and cryptic.

But HTT in March announced a signed agreement with Slovakia to “explore building” an actual Hyperloop route, while Hyperloop Technologies released drone footage earlier this year that shows building progress on its Nevada site.

Updates on track testing may not be far off.