The Design of Implicit Pedestrian-Autonomous Vehicle Interactions
Automotive manufacturers and researchers have posited that pedestrians will feel uncomfortable crossing in front of driverless vehicles—autonomous vehicles that lack visible human operators. Interface concepts based on explicit communication such as displays, lights, or projections have been developed to indicate to pedestrians that it is safe to cross. However the underlying need for such interfaces, and their efficacy, have not been thoroughly explored in on-road settings. We demonstrate how a visibly driverless vehicle’s motion and engine sound can communicate that it is safe to cross to pedestrians. We conducted field experiments in everyday traffic and interviewed unsuspecting pedestrians. We then analyzed video of each interaction to evaluate responses to the vehicle. While the novelty of a driverless vehicle did surprise some, many did not even notice its autonomous nature. Most pedestrians reported positive experiences, and all crossed in front of the vehicle without the need for explicit communication.This work challenges the assumption that driverless vehicles will need explicit displays to replace driver-pedestrian communication at crosswalks, and contributes design requirements for socially appropriate stopping behavior for autonomous vehicles. In doing so, the work brings automotive design a step closer to solving a critical human factors problem that could hinder the widespread adoption of autonomous vehicles.