A recent investigation undertaken by the University of Nottingham engaged in a captivating experiment where pedestrians were deceived by an incognito individual assuming the guise of a car seat, creating the illusion of an autonomous vehicle. The study aimed to delve into pedestrians’ reactions to diverse visual displays known as External Human-Machine Interfaces (eHMIs) positioned in the front of self-driving cars.
To execute the experiment, scholars navigated a vehicle around the university campus with a concealed “phantom driver” in the driver’s seat. Across multiple days, the phantom driver skillfully operated the car while showcasing various designs on the eHMI to convey the vehicle’s behavior and intentions to pedestrians. These designs encompassed eyes and a countenance, accompanied by concise messages such as “I have observed you” or “I am yielding.”
Cameras strategically positioned at the front and rear of the vehicle captured the responses of pedestrians to the eHMI displays, while researchers stationed outside the car requested pedestrians to partake in brief surveys.
David R. Large, a Senior Research Fellow at the University of Nottingham, explicated the study’s objective, articulating its intention to scrutinize pedestrians’ interactions with autonomous cars as part of the ServCity project, which concentrated on the development of infrastructure for self-driving vehicles in the UK.
The distinctive methodology was devised to observe reactions and discern designs that would instill the highest levels of confidence in pedestrians crossing the thoroughfare.
Upon amassing data from 520 instances of pedestrian interactions and conducting 64 surveys, the authors of the study meticulously scrutinized the information to derive invaluable insights into individuals’ attitudes and behaviors concerning different eHMI displays and autonomous vehicles.
Professor Gary Burnett, Head of the Human Factors Research Group and Professor of Transport Human Factors, expressed contentment with the findings. He remarked that a significant portion of respondents regarded the external HMI as a crucial factor when deliberating on whether to traverse the road, indicating promising prospects for further exploration in this domain.
Among the eHMI displays, those featuring explicit eyes garnered the most visual attention and received high ratings for trustworthiness and lucidity, rendering them the preferred choice. Conversely, the implicit LED strip was perceived as less perspicuous and evoked lower levels of trust.
Are we ready for interacting with robots?
In an enchanting revelation, the researchers discovered that despite most survey participants believing the car was genuinely devoid of a driver, pedestrians continued to employ manual gestures, such as expressing gratitude towards the vehicle. This finding underscores the inherent politeness of humans, even in their interactions with purported robots, thereby imparting an endearing dimension to the study’s outcomes.