Freight-on-transit: A systematic review centered on freight needs, methods, and real-world implementations

Transportation systems face spatial constraints that limit infrastructure expansion and complicate freight movement in dense city centers. Freight on Transit (FOT)—the shared use of public transit vehicles and infrastructure for goods transportation—has emerged as a strategy to improve last-mile logistics, reduce congestion, and support environmental goals. This research conducts a systematic review to consolidate current research on the methodological frameworks, operational strategies, and institutional dimensions of FOT. A total of 51 peer-reviewed studies were analyzed, covering both qualitative and quantitative approaches, with topics ranging from optimization models and simulation techniques to stakeholder analysis and policy frameworks. While the review examines FOT research broadly, it also expands the discussion on freight-specific considerations, such as commodity type, geographic context, and time-of-day factors, which are essential for assessing the feasibility, scalability, and policy relevance of integrated transit-freight operations. These aspects, although not consistently addressed across all studies, represent critical parameters influencing service design, operational performance, and practical implementation. Key findings highlight that technical feasibility is well-supported by modeling studies, but political, institutional, and regulatory barriers remain significant challenges to real-world implementation. Research efforts are heavily concentrated in urban environments, with limited empirical validation and few rural applications. This review contributes to the literature by providing a structured synthesis of FOT research and emphasizing the freight requirements that shape operational design, policy frameworks, and decision-making. The findings offer guidance for researchers, practitioners, and policymakers working to advance integrated, multimodal urban logistics solutions.