The valorization of biomass residues is increasingly recognized as a strategic pathway for advancing the green transition and reducing reliance on fossil-based energy and materials. Within this context, undervalorized bioresources play a key role in developing circular and place-based value chains. Roadside vegetation, generated through routine road maintenance, represents a recurrent and locally available biomass stream that remains underutilized, despite its potential contributions to renewable energy production, nutrient cycling, and territorial bioeconomy strategies. In Europe, the road network exceeds 6.5 million kilometers, producing an estimated 5 to 13 million tons of biomass per mowing cycle, most of which is still treated as waste. This article presents a scoping review of this emerging field, resulting in 43 peer-reviewed studies on roadside biomass valorization, analyzing technological pathways, methodological orientations, and sustainability dimensions through an original Regenerative Territorial Sustainability Framework (R-TSF). The results show that research remains dominated by experimental and process-based studies on anaerobic digestion, hydrothermal and thermochemical conversion, with strong environmental assessment, but limited integration of social, political, and governance dimensions. The synthesis indicates that current approaches remain largely technocentric, emphasizing conversion efficiency over multi-actor coordination and territorial integration. Advancing toward regenerative bioeconomy strategies requires aligning roadside biomass valorization with inter-municipal governance, adaptive regulatory frameworks, and place-based planning that connect energy, mobility, waste, and biodiversity objectives. Overall, the review demonstrates that roadside biomass can evolve from a maintenance residue to a regenerative territorial resource, one capable of supporting ecological restoration, institutional learning, and locally rooted circular value creation.