Sustainable containment of hazardous road spillages: Design and experimental assessment of a low-maintenance system

Road accidents involving vehicles transporting hazardous substances pose serious environmental risks, particularly to soil and water resources. To address this, the Portuguese Road Authority requested the development of a passive system to mitigate the impacts of accidental fuel spills in environmentally sensitive areas. After reviewing existing technologies, a prototype system was designed and tested, tailored to Portuguese road infrastructure and climatic conditions. The system is based on hydrocarbon separation principles as per European Standard EN 858. Experimental testing was conducted using a 1:10 scale physical model to minimize scaling effects while limiting the use of toxic hydrocarbons (diesel). Five scenarios were simulated, including combined fuel spill and rainfall events, to evaluate the system’s performance under realistic conditions. The model demonstrated effective containment and separation capabilities in all scenarios - a maximum of 9.94 mg/l under the most critical scenario, and an average of 0.31 mg/l in all other scenarios; both values well below the 100 mg/l limit set by EN 858 for gravitational systems. The results confirm the feasibility of employing passive systems to manage accidental fuel spills on roads, offering a practical solution for safe road operation and environmental protection.