The article discusses the challenges and complexities faced by fleet operators in decarbonising road transport. Fleet operators are currently under pressure to adapt to rapidly changing technological advancements, commercial demands, and regulatory requirements in a competitive market environment. While the focus is primarily on battery electric vehicles for medium- and heavy-duty fleets, the potential role of hydrogen in long-haul truck and coach segments is also highlighted. The overarching goal for fleet operators is to maintain or enhance business operations while transitioning towards decarbonisation. Balancing external factors such as market dynamics and regulations with internal considerations like technology investments and financing strategies is essential. Decisions around powertrain composition, charging infrastructure, and support for drivers and technicians are critical in ensuring safe and efficient fleet operations. The article emphasizes the importance of starting the transition now to avoid falling behind and losing a competitive edge. Collaboration among stakeholders, including fleet operators, customers, energy suppliers, and partners, is seen as a key accelerator for the transition. Specific challenges discussed in the article include the impact of vehicle technology choice on operations, considerations for zero-emission vehicles, the importance of proper charging and route management for heavy-duty electric vehicles, and the need for collaboration to overcome challenges in public charging infrastructure for trucks.