Ford trials pedestrian-autonomous car interaction

Latest test used white, purple and turquoise lights in a roof-mounted bar

Published: February 10, 2019, 4:30 PM
Updated: November 21, 2021, 2:56 PM

Ford autonomous vehicle with light bar

One of the leaders in the development of autonomous vehicles, Ford recently took the streets of Cologne (Germany) to test out if pedestrians can understand autonomous vehicles communicating with them through light signals.

The test served two purposes — to see if pedestrians “trusted” a driverless vehicle, and to see if different light colours and combinations were more easily recognized and understood, in the way that drivers communicate through hand-gestures, head movement and even by eye-to-eye contact.

As with prior tests, Ford did not actually use a car without a driver, but put a driver disguised as a car seat. In this manner, the incognito driver could gauge pedestrian reactions, while a rear-seat rider could also analyze the goings-on, while furthering the notion that the car was being driven autonomously.

“Fundamentally, people need to trust autonomous vehicles and developing one universal visual means of communication is a key to that,” said Thorsten Warwel, Ford of Europe core lighting manager. “Turning someone into a ‘Human Car Seat’ was one of those ideas when there was a bit of a pause and then the realisation that this was absolutely the best and most effective way of finding out what we needed to know.”

The latest test was conducted in conjunction with Germany’s Chemnitz University of Technology, using white, purple and turquoise lights located in a roof-mounted light bar. Previous tests in the US used only white lights in a light-strip at the top of the windshield. Separate tests also surveyed light-locations in the grille and integrated into the headlamps, with no clear preference emerging.

The end result was that pedestrians were able to notice the lights from as far as 500 metres away, and there seemed to be a high-level of acceptance and trust from pedestrians as to the intentions of the vehicle. Surveyed following their interaction with the “driverless” vehicle, pedestrians conveyed a preference to the turquoise light, which was more noticeable than white and less confusing than purple (which some mistook for red).

The next step is for engineers to further fine-tune the light signals to make sure there is absolutely no miscommunication.

Ford is collaborating with several industry organizations, including the Society of Automotive Engineers (SAE) and the International Organisation for Standardisation (ISO), on a program to create an industry standard for communicating autonomous vehicle intent.

In North America, Ford has previously tested, and is currently testing, autonomous vehicles on public roads in Detroit, Pittsburgh, Miami and Washington DC.