When are consumers ready for autonomous delivery robots? Functional thresholds and affective levers in urban last-mile delivery

Autonomous delivery robots (ADRs) are becoming a practical option for urban last-mile logistics, but their implementation depends on both technical feasibility and user perceptions of usability, reliability, and service experience. This study examines the user-side conditions that shape acceptance of ADR services and treats behavioural intention as an indicator of service acceptance. Drawing on the cognition-affect-conation framework, this study combines partial least squares structural equation modelling (PLS-SEM), importance-performance map analysis (IPMA), and necessary condition analysis (NCA) to examine how individual-technology fit and consumer-perceived delivery-task fit (task-technology fit) are associated with satisfaction, trust, and attachment, and how these affective responses are associated with behavioural intention. Based on survey data from 443 consumers recruited nationwide through an online panel in China, the results support the proposed mediation-oriented C-A-C pathway from fit evaluations to behavioural intention through affective responses. Attachment shows the strongest relationship with behavioural intention within the proposed model, while attachment and consumer-perceived task-technology fit meet the practical necessity criterion for high behavioural intention in this sample, without being sufficient conditions. Theoretically, the study extends ADR acceptance research by distinguishing factors associated with higher behavioural intention from conditions that must reach a minimum level. Practically, the findings suggest that ADR providers should maintain reliable task performance and improve service interactions that strengthen user attachment.