Background The use of External Car Displays (ECDs) in Autonomous Vehicles (AVs) has been verified as an effective means of communication to replace driver cues. However, there is still limited information available on child pedestrians’ experiences with ECDs as particularly vulnerable road users and the design characteristics of ECDs that impact the user experience have not been thoroughly analyzed. This study examines the design characteristics of ECDs, including communication style and visualization type, and their effect on child pedestrian trust and perceived safety.
Methods To investigate the influence of ECD design concepts on child pedestrians’ trust and perceived safety, we designed a within-subject study with 2 (communication styles: advisory and informative) × 3 (visualization types: text, sign and symbol) experiments. Six design concepts were presented in videos and randomly shown to the participants, who were elementary school students with a range of ages from 10 to 12 years old. We collected information about pedestrian trust and perceived safety from the answers to questions that used a 4-point Likert scale.
Results The results showed that the perceptions of child pedestrians with regards to the affirmations and uncertainty of information components in ECDs have a substantial impact on their level of trust and perceived safety towards AVs. Therefore, it is recommended to address these affirmations and uncertainties in the design of a trustworthy and safe ECD.
Conclusions This work contributes to a deeper understanding of AV-pedestrian communication from the perspective of child pedestrians and has implications for ECD design practices. Although the visualization type in this study can offer a new perspective for designing ECD concepts in future studies, we suggest that more design concepts be verified, with a specific focus on the sign and symbol category.