COMPARATIVE SAFETY ASSESSMENT OF BATTERY ELECTRIC AND HYDROGEN FUEL CELL VEHICLES IN ROAD TUNNELS

The rising prevalence of battery electric vehicles (BEVs) and hydrogen fuel cell electric vehicles (FCEVs) introduces novel safety problems for road tunnels, where restricted environments can markedly amplify the intensity of flames and unintended energy discharges. Despite comprehensive study on the safety of battery electric vehicles (BEVs) and hydrogen fuel cell vehicles, both technologies have predominantly been examined in isolation, constraining direct comparisons regarding their influence on tunnel safety. The article provides an analytical and comparative safety assessment of Battery Electric Vehicles (BEVs) and Fuel Cell Electric Vehicles (FCEVs in road tunnels, pointing out the most important differences concerning danger potential, development of fires, and behavior of fires in road tunnel ventilation systems. The thermal runaway processes that occur in lithium ion batteries within battery electric vehicles (BEVs) will be compared and contrasted with hydrogen emission scenarios that occur within fuel cell electric vehicles (FCEVs), including controlled emission via thermally activated safety systems. The key aspects of heat evolution dynamics, toxic gas release, flame behavior, and emergency response are analyzed by employing known tunnel safety principles and data presented in the scientific literature. The findings indicate that risks associated with electric vehicles are prominent in relation to long-term heat evolution, as well as high amounts of smoke and toxic gas, while risks related to hydrogen fuel cells are prominent in terms of short-term high-intensity thermal radiation caused by hydrogen jet flames. The findings clearly indicate that risks associated with electric vehicles and hydrogen are distinct in their nature and cannot be taken care of by the application of one safety strategy alone. The findings underscore the importance of accounting for the technology-specific risk in tunnel design, operation, and emergency response systems.