SkyTran is a system of small, automated maglev capsules that run on elevated rails, and a working demonstration system is scheduled for completion in Tel Aviv at the end of 2016.

SkyTran is the latest iteration of the Personal Rapid Transit (PRT) concept. PRT aims to combine the privacy and flexibility of a car with the efficiency of mass transit, most often by making small vehicles on rails available on-demand to individuals or small groups of riders—no train or bus schedules to worry about. There have been prototypes and early operational examples going back to the 1970s, including the German “Cabintaxi” concept and Western Virginia University’s enduringly effective system.

SkyTran was first cooked up 25 years ago by engineer Doug Malewicki, who has had a hand in building everything from the Apollo Saturn V rocket to Evel Kneivel’s jet bike to a car-eating dino-bot. SkyTran’s advances on those early PRT projects include very light two-person pods, which run suspended from a guideway not much bigger around than your leg. That rail is held up by supports about the size of telephone poles, with all the pieces built off-site for quick assembly.

“It can spread out across the city in, literally, a week or two,” says skyTran CEO Jerry Sanders, speaking to Fortune from Tel Aviv, where he’s helping oversee construction.

That speed helps make construction remarkably cheap—less than $10 million per mile, around 1/10^th of the steadily-climbing cost of urban light rail. Some of that savings is simply because skyTran doesn’t need nearly as much right-of-way.

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The system is also cheap to run, with a patented passive maglev system that makes the pods hyper-efficient, and computer controls that dispense with human operators. The system will also let passengers summon or schedule pods to particular locations using their smartphones—kind of like an Uber for trains, except this is an Uber with a top speed of, according to Sanders, 150 miles per hour. Pods shunt off to sidings to drop off or pick up riders, letting everyone else on the system keep moving until they reach their own destination.

“Once you get into a skyTran vehicle,” Sanders says, “You’ll never want to take any other mode of transportation.”

This isn’t just technology that’s slick for its own sake. The cost advantage in particular could be game-changing, because it’s relatively easy to finance a core system. Then private enterprises, such as malls and hotels, would be motivated to finance spur lines to their own doorsteps—not just because they make access easier for guests, but because low capital costs help make skyTran lines themselves profitable. Sanders says the charge to users will be “a little bit more than a bus, a little bit less than a taxi.”

Though much of this is still theoretical, skyTran is very close to becoming a reality. The Tel Aviv demonstration system is aimed at certification by the Israeli government, but Sanders says the company is proceeding in parallel with a number of projects, including a design for the city of Natanya, north of Tel Aviv, and a proposed system for Charles de Gaulle Airport.

There are still plenty of uncertainties about where skyTran could fit into a city’s overall transit picture. Depending on variables like follow distance, load times, and network density, a skyTran system might or might not be able to move as many people as a conventional light rail or rapid bus system. And, of course, bringing something this complex into the real world always involves uncertainty—the current target date for the demonstration system already represents a delay of almost a year from previous goals.

But with a real, working system online, skyTran would have an edge in a transit technology sector that is looking increasingly dynamic.

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