Design and evaluation of assistive prototypes for visually and hearing-impaired passengers in autonomous public transportation buses

Autonomous buses represent both a significant advancement in public transport and a source of novel challenges with respect to inclusive mobility, particularly concerning accessibility for individuals with visual and hearing impairments. The absence of onboard personnel renders traditional models of interaction and assistance ineffective, thereby increasing the risk of exclusion for passengers with sensory limitations and underscoring the urgent need for alternative, accessible solutions. In response to this challenge, key accessibility barriers were identified through a user-centered design approach. Based on these findings, a set of assistive design concepts was developed, specifically addressing the needs of visually and hearing-impaired user groups. The proposed solutions were deliberately grounded in low-complexity, widely available technologies to facilitate straightforward implementation and long-term scalability, without compromising usability or compliance with accessibility standards. This paper presents the resulting concepts, which were realized as functional prototypes and subsequently evaluated within a true-to-scale autonomous bus mockup in a controlled laboratory environment. The simulated ride experiences emulated realistic public transportation scenarios through the integration of ambient vehicle sounds, automated voice announcements, and synchronized visual display systems, thereby creating an immersive and ecologically valid testing context. The study’s findings indicate that even relatively simple, well-integrated interventions, such as auditory and visual guidance elements, multimodal feedback mechanisms, and redundant communication channels, can significantly improve spatial orientation, perceived safety, and situational awareness among passengers with visual and hearing impairments. These results emphasize the necessity of embedding accessibility considerations at the earliest stages of autonomous mobility system design. Importantly, the research demonstrates that inclusive design can be effectively achieved not through complex or cost-intensive innovations, but through the strategic and thoughtful application of existing technologies, informed by the specific needs of diverse user populations.