A Taxonomy of Vulnerable Road Users for HCI Based On A Systematic Literature Review

Recent automotive research often focuses on automated driving, including the interaction between automated vehicles (AVs) and so-called “vulnerable road users” (VRUs). While road safety statistics and traffic psychology at least define VRUs as pedestrians, cyclists, and motorcyclists, many publications on human-vehicle interaction use the term without even defining it. The actual target group remains unclear. Since each group already poses a broad spectrum of research challenges, a one-fits-all solution seems unrealistic and inappropriate, and a much clearer differentiation is required. To foster clarity and comprehensibility, we propose a literature-based taxonomy providing a structured separation of (vulnerable) road users, designed to particularly (but not exclusively) support research on the communication between VRUs and AVs. It consists of two conceptual hierarchies and will help practitioners and researchers by providing a uniform and comparable set of terms needed for the design, implementation, and description of HCI applications.