When Adam Tuss took a peek inside what he thought was a driverless van in Arlington, Va., he saw something that terrified him — human hands and legs protruding from the driver-side seat.

"It was like a horror movie because it's so not what you were expecting," the NBC reporter told As It Happens guest host Rosemary Barton.

Tuss, a transportation reporter, was out looking for an driverless minivan that had been spotted around the city when he made the bizarre discovery.

"I couldn't believe what I was actually seeing. I could not believe that there was a half-man, half-car seat that was pretending to be an autonomous vehicle driving around the streets of Arlington, Virginia."

When he recovered from his initial shock, Tuss did what any good reporter would do — he grilled the man.

In a Twitter video that has been retweeted more than 1,400 times, Tuss can be heard yelling at the van: "Brother, who are you? What are you doing? I'm with the news, dude."

"That is the way I talk, so when I talk to people or I approach them on the street, I find that that completely disarms them," Tuss said.

However, it did not disarm Mr. Car Seat.

"All credit to this man. Stoic. Nothing happened. He just kept his hands on the wheel, as if I didn't even exist."

When the light changed, Mr. Car Seat took off with Tuss and his photographer in pursuit. They followed the van for 20 minutes, but then they lost him.

After Tuss broke news of the ruse on NBC, he got a call from the Virginia Tech Transportation Institute (VITI) saying the man in the car seat costume worked for one of its research projects.

Virginia has no laws against driverless cars and Gov. Terry McAuliffe recently declared he wants the state to become "the capital of automated vehicles."

Contacted for comment by As It Happens, VITI e-mailed a link to a page that describes "studying human behavior in the presence of new technology in the real world."

"These researchers spent so much time camouflaging him in this vehicle because what they were really trying to do is see how the public reacted to a car that had no driver," Tuss said. "And man — they got a reaction."

In the meantime, Tuss is basking in the glow of his viral scoop.

"We do have an I-Team at our station and after this report they said they need to make me an honorary member of the investigation team," he said.

"So, for what it's worth, this has elevated me in the ranks of my local station."