Ford and Virginia Tech are shedding a light on pedestrian and self-driving car communication, and testing it with a clever disguise.

When pedestrians and drivers need to communicate, it’s a simple task. A gesture as subtle as a nod can do the trick. Eye contact, a wave, a flash of the headlights – all easy ways for a driver and a pedestrian to share a very important message. Autonomous cars can’t wave or make eye contact or even nod at a pedestrian. But while connected networks let cars communicate with each other, they still need to communicate with pedestrians, cyclists, and conventional cars.

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Ford, along with Virginia Tech Transportation Institute, conducted a study of real users to test a new method of communicating with pedestrians.

“Understanding how self-driving vehicles impact the world as we know it today is critical to ensuring we’re creating the right experience for tomorrow,” said John Shutko, Ford’s human factors technical specialist. “We need to solve for the challenges presented by not having a human driver, so designing a way to replace the head nod or hand wave is fundamental to ensuring safe and efficient operation of self-driving vehicles in our communities.”

The researchers decided that lights are the best way to communicate. Displayed text and symbols were rejected because of the need for all people to understand the same language. The test used three light signals to test the intent of the communication. Two side to side lights means the vehicle is going to yield. A solid white band indicates full autonomous driving, and a blinking light means that the car is going to accelerate from a stop.

The researchers needed to test their theories but didn’t have an actual autonomous car to do it. So they faked one. A staffer put on a special outfit that made them look like an empty driver’s seat. They then drove around Arlington, Virginia, in a Ford Transit Connect van. The faux autonomous Ford covered over 1,800 miles and used the signals more than 1,650 times.

Cameras captured the pedestrian and road user behaviour. Researchers will use that data to understand how road users change their behaviour in response to self-driving vehicles and the signals.

Ford is currently working with other industry organizations including SAE and the International Organization for Standardization to set standards for self-driving car communication. It is also working on alternative systems to communicate with the visually impaired, something the lights are not able to do.