A Sustainable Development Process for Visually Interactive Companions in Ubiquitous Passenger Information Systems

In today’s increasingly complex and multimodal mobility environments, passengers are confronted with fragmented information, inconsistent user interfaces, and limited context-adaptivity across public transport systems and services. These challenges hinder a positive mobility experience, reduce trust, and limit the broader adoption of sustainable transport options. This paper addresses these gaps by introducing a structured, user-centered development methodology for Visually Interactive Companion Technologies in Ubiquitous Passenger Information Systems (VICUPISs). The approach incorporates system characteristics, contextual factors, and a comprehensive process framework. Drawing on applied research and development projects, the methodology defines a five-phase development cycle—from field to concept and back—combining expert insights and user participation across iterative development stages. A central contribution is the integration of a rich context model spanning eight dimensions, enabling adaptive, multimodal, and personalized interaction across mobile, embedded, and public displays. The methodology also incorporates AI-supported adaptivity and addresses the resulting challenges for usability evaluation. Sustainability is considered at three levels: resource-efficient system development, long-term extensibility and adaptability of digital systems, and support for a modal shift toward environmentally friendly public transport. The proposed methodology offers a replicable and transferable foundation for designing human-centered, future-ready information systems in public mobility, complemented by practical heuristics and insights from two case studies of sustainable transport ecosystems.