By Jingwen Hu
The future of automobiles is electric, but many people worry about the safety of today’s electric vehicles.
Public opinion about EV crash safety often hinges on a few high-profile fire incidents. Those safety concerns are arguably misplaced, and the actual safety of EVs is more nuanced.
I’ve researched vehicle safety for more than two decades, focusing on the biomechanics of impact injuries in motor vehicle crashes. Here’s my take on how well the current crop of EVs protects people:
The burning question
EVs and internal combustion vehicles undergo the same crash-testing procedures to evaluate their crashworthiness and occupant protection. These tests are conducted by the National Highway Safety Administration’s New Car Assessment Program and the Insurance Institute for Highway Safety.
These analyses use crash test dummies representing midsize male and small female occupants to evaluate the risk of injuries. The tests can evaluate fire hazard either caused by thermal runaway – when lithium-ion batteries experience rapid uncontrollable heating – in ruptured EV batteries or gas tank leaks of internal combustion vehicles.
None of the Insurance Institute for Highway Safety crash tests of EVs have sparked any fires. New Car Assessment Program crash test reports yield comparable findings. While real-world data analysis on vehicle fires involving EVs is limited, it appears that media and social media scrutiny of EV fire hazard is blown out of proportion.
Weighty matters
What stands out about EV safety is that crash test results, field injury data and injury claims from the Insurance Institute for Highway Safety all reveal that EVs are superior to their internal combustion counterparts in protecting their occupants.
This EV advantage boils down to a blend of physics and cutting-edge technologies.
Thanks to their hefty battery packs positioned at the base of the car, EVs tend to carry considerably more weight and enjoy lower centers of gravity than conventional vehicles. This setup drastically reduces the likelihood of rollover accidents, which have a high rate of fatalities. Moreover, crash dynamics dictate that in a collision between two vehicles, the heavier one holds a distinct advantage because it doesn’t slow down as abruptly, a factor strongly linked to occupant injury risks.
On the technology side, most EVs represent newer models equipped with state-of-the-art safety systems, from advanced energy-absorbing materials to cutting-edge crash avoidance systems and upgraded seat-belt and air-bag setups. These features collectively bolster occupant protection.
Where risks do rise
Unfortunately, EVs also present numerous safety challenges.
While the inherent weightiness of EVs offers a natural advantage in protecting occupants, it also means that other vehicles bear the burden of absorbing more crash energy in collisions with heavier EVs. This dilemma is central to the concept of “crash compatibility,” a well-established field of safety research.
Consider a scenario in which a small sedan collides with a heavy truck. The occupants in the sedan always face higher injury risks. Crash compatibility studies measure vehicle “aggressivity” by the level of harm inflicted on other vehicles, and heavier models are almost always deemed more aggressive.
In addition, the increased energy associated with impacts from heavier EVs, particularly electric pickups, poses significant challenges for highway guardrails. Moreover, EVs – especially those operating silently at low speeds – pose increased risks to pedestrians, bicyclists and others who may not hear the EVs approach.
Better technologies, better safety
While EVs offer safety advancements for their own occupants, it’s crucial to acknowledge and tackle the safety concerns they pose for others on the road.
I believe that technological advancements will serve as the primary catalyst for overcoming the safety hurdles faced by EVs. Lightweight materials, more powerful sensing technologies and safety algorithms, improved seat belts and better air bags will play pivotal roles in addressing these challenges.
Moreover, the tight connection between EVs and rapidly evolving computing capabilities is likely to foster the development of new safety technologies.
Jingwen Hu is Research Professor of Mechanical Engineering at the University of Michigan.
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Jim says
No offense to the author but I have to ask…. Are people driving conventional gas/diesel vehicles in more danger in a collision with and EV than when in a collision with an Excursion, Expedition or Suburban? Just curious. Unless that is a fact, I think I’m willing to “risk” having an EV hit me knowing that at least those vehicles are an attempt to ween us all off fossil fuels.
Ray W. says
An interesting tidbit about electric vehicles.
In January 2023, the Antelope Valley Transit Authority (northern Los Angeles) issued a press release to mark their electric bus fleet passing 10 million miles travelled. Starting in 2016, the ATVA began switching to an all-electric fleet; it now has 57 buses, 24 commuter coaches and 8 transport vans. Including the cost for electricity to recharge batteries, the Authority announced its net savings on fuel costs thus far at $3,375,000, or just under 38 cents per mile. The release did not quantify the gallons of engine oil, transmission fluid, and gear oil saved, or maintenance hours to change the fluids saved. Initial purchase prices were likely higher and other maintenance factors were not made available, but savings on brake repairs not performed or brake pads not replaced due to regenerative braking were likely significant.