Autonomous cars could use emojis to ‘talk’ to cyclists

Cars and bicycles sometimes share a troubled relationship on the road, which could become even more complicated when self-driving vehicles take to the road in coming years.

Digital displays on the exteriors of autonomous cars could help cyclists stay safe on the roads of the future and help reduce the risk of collisions between cars and bikes, according to researchers and psychologists at the University of Glasgow in Scotland. 

Animated representations of virtual drivers, traffic-light-like projections onto the road or emojis displayed on their surfaces could allow robotised cars to share advance warning of their movements with bike riders.

The recommendations are based on human-computer interaction research conducted at the university, which is exploring ways to replace the complex non-verbal language currently shared between drivers and cyclists once cars begin driving themselves.

The team’s paper, “Pimp My Ride: Designing Versatile eHMIs for Cyclists”, will be presented at the AutoUI conference in Ingolstadt, Germany, in September. 

Previous research from the same team suggested that future generations of self-driving cars should “learn the language of cyclists” to help them safely share the roads with bikes. Their new research goes a step further. 

The paper outlines the outcomes of workshops with cyclists that investigated how that language should be designed, displayed and interpreted to help reduce the risk of collisions between cars and bikes. 

“There’s an urgent need to develop clear and consistent ways for cyclists to interact with autonomous vehicles, which are set to be a common sight in the future,” said Stephen Brewster, of the University of Glasgow’s School of Computing Science, who led the research.

Reproduce dialogue

“Over the years, drivers and cyclists have developed their own language of gestures and other non-verbal cues to help negotiate the roads safely. That language helps both parties decide who has right of way, for example, or signal an intention to merge lanes. 

“Currently, self-driving cars lack the ability to communicate with cyclists with anything close to that level of detail or nuance, which could make cycling, scootering and wheeling much more dangerous unless we find a way to reproduce that dialogue.”

Brewster says external human-machine interfaces (eHMIs) such as digital displays on the outside of vehicles are one promising solution to the problem.

The researchers gathered 12 volunteers in a car park to consider how autonomous vehicles might communicate with cyclists in different traffic scenarios, with bikes placed anywhere around the car. The volunteers were encouraged to draw directly on the surfaces of the car to show where they might want to see displays, with details of how the displays might work.

The virtual driver concept would embed displays in autonomous vehicles’ windscreens, side windows and mirrors. Those displays would show cyclists a digital avatar of a human driver. The avatar would use their hands and head to gesture using the social cues that bike riders are currently accustomed to exchanging with real drivers without cyclists having to learn any new methods of communication.

Displays on autonomous vehicles’ exteriors would display traffic signs to advise riders if the car was going to yield or proceed. The cars would also project colours onto the road around them, with green areas safe for cyclists to enter and red spaces where cyclists should avoid.

The emoji-car design would use a roof-mounted display to display emoticons to communicate with cyclists. Left and right arrows would echo indicators on the car and lightning symbols would show intent to accelerate. 

A LightRing would use a band of LEDs wrapped around the car paired with a sensor on the roof. The LightRing would use colours and animations to communicate with pedestrians and cyclists. The car could signal proximity awareness by displaying an amber patch that grows as people get closer. Intentions to change speed could be accompanied by strokes of light that get faster as the car speeds up and slows down in the opposite direction as it decelerates. 

Ammar Al-Taie, co-author of the paper, said the goal is to allow cyclists to continue the behaviours they have already learnt in keeping safe on the roads. To do that, a unified design language which provides consistent messaging is key.