Electric Vehicle Fires in Tunnels – Do We Need to be Concerned?

With the increased uptake of electric vehicles (EVs), the question about their fire risk has come into focus.  

The increasing number of EVs on the road means that more EV-related fire incidents will likely occur. EV fires differ from fires of conventional internal combustion engine vehicles (ICEVs). They may be hotter, last longer, are more difficult to extinguish, and create a different mix of pollutants. They may also require a different approach to building and operating road infrastructure such as road tunnels.  

In that context, the NTRO has looked at the fire hazards posed by battery electric vehicles (BEVs), the most common type of new passenger EVs today, and fuel cell electric vehicles (FCEVs). The research focuses on high-risk fire incidents in road tunnels where potentially dangerous EV fires may be triggered if EVs are involved in accidents. This work draws on Australian tunnel design criteria, insights gathered from experiments and case studies, as well as feedback from industry representatives.  

The research finds that significant additional or unmanageable risks imposed on tunnel structures, fire responders, the environment, and human health are unlikely, in comparison to a fire involving an ICEV. However, there are challenges with EV fire reignition and removal from tunnels remain. Nevertheless, these conclusions are valid for an isolated passenger BEV or FCEV fire, and questions remain about the consequences of multiple simultaneous EV battery fires or fires involving heavy EVs such as electric buses or trucks with high-capacity batteries. Also, the fire risk of future EVs with different battery technologies hitting the market remains uncertain.  

Hence, it is important that tunnel operators and emergency responders remain vigilant and prepared. Future work should target fires of heavy BEVs and FCEVs which pose a higher risk compared to passenger cars. In addition, risks associated with EV fires in other underground infrastructures beyond tunnels, such as underground carparks or multi-story parking lots, should be investigated. 

If you would like to know more, we encourage you to come to the NTRO International Technical Conference at our Port Melbourne facility from 25th to 27th of October 2023. To get in touch with us about future fuel vehicles, email robert.kochhan@arrb.com.au.