Barriers to fuel cell cargo bike adoption in urban logistics: a multi-level transition analysis

European municipalities are increasingly pivotal in advancing sustainable urban freight systems. This paper examines the potential of Fuel Cell Cargo Pedelecs (FCCPs) as innovative alternatives to diesel and battery-powered logistics vehicles. Despite growing technological promise and policy interest in zero-emission logistics, the widespread integration of hydrogen-powered cargo bikes remains limited and underexplored in academic research. Addressing this gap, the study applies a dual framework combining the Multi-Level Perspective (MLP) and Rogers' Diffusion of Innovations theory to analyze both structural and behavioral factors shaping FCCP adoption. Drawing on a mixed-methods assessment of FCCP deployment in multiple cities within the Interreg North-West Europe project, the study systematically contrasts stakeholder expectations and policy visions prior to deployment with operational experiences and institutional realities observed during implementation, enabling identification of mismatches between technical promise and socio-economic constraints. Findings show that while FCCPs can be operated reliably in selected delivery contexts, they did not demonstrate meaningful advantages over conventional electric cargo bikes in real-world conditions. The theoretical benefits of hydrogen, extended range and rapid refueling, were rarely required, while the hydrogen system introduced additional technical, organizational and regulatory complexity. These challenges were amplified by fragmented standards, limited refueling options and elevated insurance and maintenance requirements. Across all MLP levels, misalignments persisted: landscape pressures generated supportive visions, but regime structures and niche conditions did not provide the institutional or infrastructural anchoring needed for broader diffusion. The study contributes to transition research by illustrating how cross-regime niche innovations face compounded alignment challenges.