Here we are, almost three years later, and the most visible milestone achieved to date are some disconnected tube sections scattered in the Nevada desert, and the selection of a Hyperloop pod design that will race on Musk’s yet-to-be-built test track. That’s not to say there isn’t progress though. Here’s the current status of the three most notable efforts to make Hyperloop a transportation reality:

Hyperloop Transport Technologies (HTT) plans to begin construction on its 5-mile, passenger-ready Hyperloop in mid-2016 . The crowdsourced initiative’s COO Bibop Gresta claimed at Davos last month that HTT will have a working Hyperloop capable of transporting passengers across central California’s Quay Valley in 36 months . (Last October, Gresta claimed the company was 32 months away from that milestone). HTT’s claims are the most ambitious of the bunch, but they’re also the most dubious.

Hyperloop Technologies Inc. (HTI) plans to have its 1.9-mile scaled-down test track up and running on the outskirts of Las Vegas before the end of 2016. The company says you’ll be able to buy a Hyperloop ticket as early as 2020 if it continues making progress at current rates. HTI has already placed some pipes in the desert , and owns some of the fledgling industry’s most impressive-looking testing equipment.

most impressive-looking Musk is taking a more reasoned and measured approach to achieve his vision. His almost 1-mile, scaled-down test track nearby the SpaceX HQ in Hawthorne California is expected to break ground in the Spring before completion in the summer. The Tesla and SpaceX CEO has not committed to commercializing the technology, but he‘s been a consistent champion of the cause.

As you can see, we’re still a long way off from having a functioning Hyperloop between LA and San Francisco. Hell, we’re a long way off from having a Hyperloop between any two major metropolitan areas. And it’s certainly unlikely to happen in Musk’s original 2020 to 2022 timeframe.

I applaud the interest that Hyperloop is generating in science and engineering

I don’t mean to bemoan the lack progress. I celebrate the work that’s brought us this far, and applaud the interest that Hyperloop is generating in science and engineering amongst students, as well as the public at large. I’m just saying that predicting things is hard. And constructing a Hyperloop at the scale required for mass transportation is fraught with complications. Some are technical, but others will be regulatory in nature. No amount of engineering knowhow, for example, can "solve" the complex web of entrenched interests backing America’s incumbent modes of transportation (planes, trains, automobiles, and boats). Hurdles that Hyperloop developers will have to face once they’ve proven the technology actually works.

Still, predicting things is fun. So, let’s do some of our own with the advantage of hindsight.