VRU Communication Systematic Review

Autonomous vehicles (AVs) are becoming increasingly important for daily mobility. As these vehicles move into public spaces, one of the biggest challenges is how they will interact safely and effectively with vulnerable road users (VRUs), especially pedestrians. Clear communication between AVs and pedestrians is not only important for safety but also for trust and public acceptance of this technology. There are already several reviews that cover related topics, including pedestrian behavior around AVs, human factors in automated driving, and the role of external human–machine interfaces (eHMIs). For example, some studies have looked at how pedestrians interpret AV signals, how trust develops, and what design strategies might help communication (Rasouli & Tsotsos, 2019; Schieben et al., 2020; Mahadevan et al., 2018; Ackermann et al., 2020; Lee et al., 2022; Zhang et al., 2024). These reviews provide useful insights, but they often focus on narrower aspects such as interface design, simulation studies, or general human–automation interaction. What is still missing is a systematic synthesis that looks directly at the interaction and communication between pedestrians and AVs across different study types. Our review aims to fill this gap by systematically identifying and analyzing empirical evidence on how pedestrians perceive, interpret, and respond to AVs, as well as how AVs attempt to communicate their intentions. This work will help clarify the state of current evidence, identify gaps, and offer guidance for future research and practice in making AV–pedestrian interaction safer and more effective. Ackermann, C., Beggiato, M., Schubert, S., & Krems, J. F. (2020). An experimental study to investigate design and assessment criteria: What is important for communication between pedestrians and automated vehicles? Applied Ergonomics, 85, 103033. https://doi.org/10.1016/j.apergo.2020.103033 Lee, Y. M., Madigan, R., Garcia, J., Tomlinson, A., & Markkula, G. (2022). Autonomous vehicles and vulnerable road users: A systematic literature review on interaction and communication. IEEE Transactions on Intelligent Transportation Systems, 23(12), 22836–22852. https://doi.org/10.1109/TITS.2022.3154728 Mahadevan, K., Somanath, S., & Sharlin, E. (2018). Communicating awareness and intent in autonomous vehicle–pedestrian interaction. Proceedings of the 2018 CHI Conference on Human Factors in Computing Systems, 1–12. https://doi.org/10.1145/3173574.3174003 Rasouli, A., & Tsotsos, J. K. (2019). Autonomous vehicles that interact with pedestrians: A survey of theory and practice. IEEE Transactions on Intelligent Transportation Systems, 21(3), 900–918. https://doi.org/10.1109/TITS.2019.2901817 Schieben, A., Wilbrink, M., Kettwich, C., Madigan, R., Louw, T., & Merat, N. (2020). Designing the interaction of automated vehicles with other traffic participants: Design considerations based on human needs and expectations. Cognition, Technology & Work, 22(1), 117–129. https://doi.org/10.1007/s10111-019-00592-5 Zhang, J., Ali, S., Petrovic, N., & Bengler, K. (2024). External human–machine interfaces for automated vehicles: A review of empirical findings and future directions. ACM Computing Surveys, 56(8), 1–35. https://doi.org/10.1145/3656376