Virginia Tech researcher Andy Schaudt uses disguises to study reactions to driverless cars. (Zhiyan Zhong,Victoria Walker/The Washington Post)

Andy Schaudt is an invisible man.

He is wearing a “seat suit” to make it look like his Ford Transit Connect van is driving itself.

His bespectacled face is obscured by a fake headrest hood. His torso is tucked behind custom-sewn upholstery armor, like the pads protecting a Yankees catcher but in meticulously chosen black and stone leather hues to mirror Ford Motor’s usually inanimate seats.

The automaker is trying to devise a “standard visual language” so its self-driving cars can communicate with humans. The company is testing a bar of flashing white lights on the windshield meant to replace the little nods and go-ahead half-waves that keep people from getting into crashes.

And that means some deception in the service of progress.

Researcher Andy Schaudt disguised himself as a car seat to test reactions of other drivers and pedestrians to a driversless vehicle. (Zhiyan Zhong/THE WASHINGTON POST)

Ford tapped a half-dozen Virginia Tech Transportation Institute researchers, Schaudt among them, to spend August tooling around Arlington pretending not to be there. They drove more than 1,800 miles and collected 150 hours of 360-degree video from six cameras mounted on their gray van.

It’s satisfying work, but it can be uncomfortable at times, jolting usual conventions in the way strangers interact.

One of Schaudt’s colleagues apparently didn’t get going quickly enough when a light turned green, prompting another motorist to speed around to the right and begin to yell. Then he saw nobody there “and said it out loud — there’s nobody driving this car,” Schaudt said.

Aggressive drivers want to employ “communication methods that aren’t exactly required for navigation,” Schaudt noted. So when they conclude there’s nobody there to scream at, “it’s a jaw dropping moment.”

Other times, it’s Schaudt and his colleagues who can get a bit thrown.

“It’s kind of awkward when you are in the vehicle and somebody’s looking right in the window at you. And it’s okay for you to look at them, because you’re behind this hood and they don’t see you,” Schaudt said. “But you still kind of look away.”

The Virginia experiment was the brainchild of Ford engineer John Shutko, who has been pushing the idea of the light bar with colleagues from other car companies around the world. He said Ford doesn’t see a competitive advantage in the research, but instead wants to share its findings as a way to improve safety and get people more comfortable with driverless vehicles.

Shutko had been spending his days thinking about the inside of autonomous cars — and how passengers will react to having no driver. How would the car need to communicate with them if it needed to change routes because of a backup, something an Uber driver could just mention casually?

As he burned through those questions, he came up with another big one.

“When you pull the driver, how’s that going to impact civilians and others on the outside of the vehicle?” Shutko said. It was somewhere between an “aha!” moment and an “Oh no!” moment.

“It was like an ‘Oh goodness!’ Now we’re going to have to think about something beyond what we normally think about,” Shutko said. It’s an opportunity, he said, years before going into production, “to start to understand how people will behave around this type of technology.”

Although Ford is among many automakers and tech firms already running self-driving cars in the country, they went with the seat-suit ruse because it was cheaper and easier.

Duke robotics expert Missy Cummings — who has raised safety concerns about a hasty driverless rollout — applauded the idea of publicly identifying the vehicles. “I want them painted flashy hot pink or something really obvious, so I know and can give them due deference,” she said.

The Virginia researchers said that they hadn’t seen evidence of people fearfully avoiding, or toying with, the van.

Shutko and his team discarded the idea of using words on the outside of the van to signal people, saying they were too confusing in a multilingual world. And he said symbols, too, can be ambiguous. Research has shown, for example, that all sorts of people don’t know what the symbol for rear defrost in their car means, he said.

So they went with lights. A solid white light is meant to signal the van is driving autonomously. A flashing light means it will be accelerating. And when two lights move side to side — some of the researchers call that the Hoff Signal, as in David Hasselhoff from “Knight Rider” — it means the van is yielding.

On a drive Wednesday to demonstrate the setup, the blue sleeves of Schaudt’s Virginia Tech shirt poked out by his knees. But he held the wheel down low so people couldn’t see them.

And they didn’t.

A cook at Cheesetique, taking a smoke break on an Arlington sidewalk, stared through the rolling van’s front windshield. Nothing.

“You could tell no one was actually driving the car,” Travis Hicks said. “Sooner or later, it’s going to be back to the future.”

Many people didn’t even seem to see the van.

An elderly woman with a dog didn’t look up as it rolled toward her. The jaywalker on her phone didn’t even notice Schaudt was there.

“For the most part, people are busy. They’re going about their day. They’re on their phone, and they’re just kind of moving through the world,” Schaudt said. “Sometimes you could drive for a few hours and nothing out of the ordinary would happen, which is a finding in and of itself.”