The mystery of the ghost-driven minivan has been solved.

And it's all the work of some university researchers.

First, let's recap: Last week, we spotted video of a driverless car that was seen cruising around Arlington, Virginia.

One witness who saw the car told Business Insider that the Ford Transit van looked a little strange and that there appeared to be nobody in the driver's seat.

Virginia doesn't have any laws preventing autonomous testing on public roads, nor a special permitting process for self-driving cars. And so, nobody, including some county officials, seemed to know who the driverless vehicle belongs to.

But that's not the weirdest part of the story. NBC4's Adam Tuss managed to track the vehicle down on Monday, and even pulled up next to the car at a stop light.

Turns out, there is someone in the driver's seat — he's just hidden in the seat, and dressed in what appears to be a bizarre camouflage designed to look like a car seat.

In the video Tuss posted, he could see the driver's hands. (NBC4 will air a segment on the odd van on Monday night.)

Check it out:

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Here's the original video:

We were stumped, and considered a variety of explanations, including the driverless van being a stealth program from a tech company or government contractor.

But it turns out, the answer has less to do with testing new technology than it does with testing the behavior of fellow humans.

A spokesperson for Virginia Tech told Business Insider that its researchers were behind the driverless car. It's part of a study to get real-world reactions to apparently driverless cars.

"The driver’s seating area is configured to make the driver less visible within the vehicle, while still allowing him or her the ability to safely monitor and respond to surrounding," according to a website about the study.

"Development of the test vehicle focused on ensuring driver safety and included several months of piloting and testing the vehicle, first in controlled areas, then in low-density areas and finally in an urban area," it continued.

It's not inconceivable to imagine another driver getting freaked out or distracted by the sight of a driverless car and potentially causing an accident, but the study was approved by the Virginia Tech Institutional Review Board, according to the study's website.