Decarbonising road freight: A scoping review and conceptual framework for alternative fuel and powertrain selection

The transition to alternative fuels and powertrains is a critical lever for road freight decarbonisation. However, these technologies present complex techno-economic and environmental trade-offs, creating a need for strategic decision support on which technologies to adopt. This systematic scoping review analyses studies that apply quantitative decision-making methods to evaluate and select alternative fuels and powertrains. Following PRISMA-ScR guidelines, an initial 6,372 articles published from 2015 onwards were identified through database searching. After screening and citation searching, 45 primary studies were included in the review. The analysis reveals that exact optimisation (n = 27) is predominantly used for fleet planning or transport and energy system transition modelling, whereas multi-criteria decision-making (n = 15) is primarily applied for strategic technology ranking and prioritisation. Metaheuristic approaches (n = 3) are largely reserved for highly complex or computationally difficult optimisation problems. The evidence base is concentrated in Europe and North America, limiting the transferability of evidence to the Global South. Multiple research and modelling gaps were also identified that affect comparability and practical usability. These include unspecified contextual boundaries, limited social impacts, narrow environmental modelling, and unspecified fuel production pathways. The primary contribution of this review is the Alternative Fuel and Powertrain Decision Framework (AFPDF). This conceptual framework combines recurring decision elements across the evidence base with modelling and reporting recommendations to structure the broader decision-making process, whilst addressing existing gaps. The AFPDF provides analysts with a transparent process for generating context-specific fuel and powertrain recommendations for road freight stakeholders, and reporting the assumptions on which those recommendations depend.