Evaluating subjective cycling safety via 360°Images and HMDs: A comparative study.

INTRODUCTION: Subjective safety is a key determinant of cycling behavior and traffic risk perception, yet it is rarely assessed systematically in infrastructure evaluation. Because perceived safety does not necessarily correspond to objective indicators such as crash statistics or design standards, reliable methods are needed to capture experiential safety dimensions relevant to research and practice. Immersive technologies such as head-mounted displays (HMDs) may provide a controlled, scalable, effort- and resource-efficient addition or even alternative to rarely conducted on-site assessments. METHOD: This study investigated whether static stereoscopic 360° images presented via an HMD can approximate real-world evaluations of subjective cycling safety. Following two preparatory studies on representativeness (N1 = 92) and usability (N2 = 20), a comparative study was conducted with two independent cohorts (N3 = 129). One group assessed a bicycle street in real traffic conditions (n = 64), while the other evaluated the same locations using twelve 360° panoramas in an HMD (n = 65). Subjective safety was measured using five items adapted from a national cycling safety survey. Bayesian independent-samples t tests were conducted to examine convergence or divergence between assessment modes. RESULTS: Findings indicated convergence for overall subjective safety (BF10 = 0.67) and perceived conflicts with motor vehicles (BF10 = 0.81), suggesting that HMD-based assessments can reproduce general safety impressions. However, participants in the HMD condition reported higher perceived conflict frequency with pedestrians (BF10 = 735.95), more obstacles (BF10 = 7.14), and lower perceived suitability for children and older adults (BF10 = 2.83). Usability ratings were highly positive. Conclusion and Practical Applications: Static HMD-based assessments seem to validly capture key aspects of perceived cycling safety while offering a resource-efficient and controlled alternative to field surveys. The approach enables systematic integration of user perception into infrastructure planning and supports the development of safer cycling environments.