Evaluating the Use of Graphic Symbols in Autonomous Vehicle-To-Pedestrian Communication

Even as autonomous vehicles (AVs) are being trialed globally, there is a growing recognition that AV technology development needs to be complemented by an understanding of how to promote acceptance of the technology and positive interactions between humans and AVs. In this study, we aim to facilitate future human-machine interface (HMI) design for AVs by focusing on enhancing A -to-pedestrian interactions using graphic messages displayed on the exterior of the vehicle. Five types of graphics were investigated using an online survey with 440 participants from Japan and Singapore. We found that pictograms were the most preferred graphic type, followed by graphics with eyes and pictogram, and graphics with eyes only. Cultural differences were also found with Japanese participants preferring graphics with eyes. Participants in both countries reported positive attitudes and emotions towards the use of these graphics in AVs in general. These results support further efforts to develop graphic messages to enhance public acceptance and AV-to-pedestrian interactions, particularly in the development of universal graphics for use with AVs.