Safety over all? How European riders evaluate advanced cyclist assistance systems (ACAS) and their features

As cycling gains traction as a sustainable transport mode, enhancing cyclists' safety has become a key priority within European policy. Among the various developments introduced, Advanced Cyclist Assistance Systems (ACAS) stand out as a promising technological innovation. However, research on their perceived value and adoption remains limited, particularly regarding user preferences and demographic differences. Aim This study aimed to examine European cyclists' evaluation of five ACAS types and their core functional features, as well as to explore demographic differences, particularly in relation to cyclists' gender and age. Method This study used the data provided by 6167 cyclists (47.4% females; 51.5% males; 1.1% others) from 19 European countries. Participants provided self-reported evaluations of five ACAS types (environmental monitoring, rider visibility enhancement, real-time information, crash prevention-assistance, and post-crash appliances) along with key features (safety contribution, reliability, ease of use, novelty, and everyday need). Results Among ACAS types, visibility-enhancing systems (designed to increase cyclists' conspicuity) and environmental monitoring technologies received the highest valuations, while real-time information systems were rated the lowest. Safety contribution was the most highly valued attribute across all ACAS features. Additionally, gender differences were observed, with female cyclists prioritizing visibility and safety-related aspects. In contrast, male cyclists –while also favoring visibility-improving ACAS– placed greater emphasis on ease of use as a core feature. Conclusion These findings highlight the importance of user-centered ACAS design and suggest that broader adoption may depend on improving system reliability, regulatory frameworks, and alignment with cyclists' needs and attitudinal factors. Future research should explore real-world ACAS implementation and long-term adoption trends to support safer and more technologically integrated cycling environments.