One of the biggest challenges facing car companies developing driverless vehicles has little do with sophisticated robotics or laser technology.

Instead, they must engineer something far more amorphous but no less important: human trust, the kind that is communicated when human drivers and pedestrians make eye contact at a crosswalk.

Surveys indicate that large portions of the public harbor deep reservations about the safety of self-driving technology, so Jaguar Land Rover enlisted cognitive psychologists to learn "how vehicle behavior affects human confidence in new technology," the British automaker said in a news release.

Their solution: virtual eyes, a large, cartoonish pair that bring to mind the plastic googly eyes you probably glued onto projects in elementary school.

The eyes have been fitted to autonomous vehicles known as "intelligent pods." Devised by a team of engineers, the eyes seek out nearby pedestrians before "looking" directly at them — silently signaling that the vehicle sees them and plans to remain stationary so they can pass, the company said.

Before and after the interaction, engineers record trust levels to determine whether human test subjects experienced sufficient levels of confidence in the pod, the company said. So far, more than 500 people have been observed interacting with the expressive vehicles, but the company hasn't released details about the interactions.

"It's second nature to glance at the driver of the approaching vehicle before stepping into the road," Pete Bennett, future mobility research manager at Jaguar Land Rover, said in a statement. "Understanding how this translates in tomorrow's more automated world is important."

Other industries have applied eyes to robots, as well. The industrial robot Baxter has a tablet-like face with eyes designed to communicate the robot's intentions to nearby human workers, such as concentration when the machine is working or sadness when it's broken.

People are uneasy about not only interacting with but riding inside self-driving vehicles. An American Automobile Association study this year found that 63 percent of U.S. drivers report feeling afraid to ride in a fully self-driving vehicle, down from 78 percent a year earlier.

Male drivers and millennials are most trusting of autonomous technology, with only half reporting fear of riding inside a fully autonomous car, according to AAA, which has begun urging automakers to educate consumers about autonomous transportation. Even though human error causes more than 90 percent of crashes, most drivers consider their driving skills better than average and are leery of handing control over to a machine.

"Americans are starting to feel more comfortable with the idea of self-driving vehicles," AAA Automotive Engineering and Industry Relations Director Greg Brannon said in February. "Compared to just a year ago, AAA found that 20 million more U.S. drivers would trust a self-driving vehicle to take them for a ride."

Jaguar Land Rover is not the only company exploring how to broadcast messages between autonomous vehicles and pedestrians.

This summer a Mountain View, Calif.-based start-up, Drive.ai, launched a pilot program in Frisco, Texas, in the Dallas-Fort Worth metroplex. The bright orange vehicles autonomously ferry people around a geo-fenced office-park complex where about 10,000 people work, eat, and shop.

The words "self-driving vehicle" wrap around their Nissan NV200 vans, and the vehicles include exterior panels with messages — such as "waiting for you to cross" — to take the place of a human driver making eye contact or gesturing with a pedestrian at a crosswalk.

Company officials have pointed out that self-driving cars still "don't understand certain complex situations such as a construction worker communicating using hand gestures."

Jaguar Land Rover's intelligent pods have yet to venture into the real world and instead operate on a "fabricated street scene in Coventry," the company said.