While the perception among American drivers is that bigger vehicles are safer, that may not necessarily be the case, a new study found.
The Insurance Institute for Highway Safety reported that the safety advantage of larger cars has its limits. Safety benefits decline as a vehicle increases in weight past the fleet average, per the study, while safety risks grow for occupants of nearby vehicles, especially in crash situations.
“For American drivers, the conventional wisdom is that if bigger is safer, even bigger must be safer still,” IIHS President David Harkey said in a statement. “These results show that isn’t true today.”
Demand for larger vehicles in the U.S. has grown steadily in recent years, prompting automakers to produce more of the bigger and profitable trucks and SUVs. According to an Environmental Protection Agency report published in 2024, the average weight of a 2023 vehicle in the U.S. was a record 4,371 pounds, 215 pounds more than the average weight of a 2019 model.
IIHS researchers analyzed vehicle crashes that occurred between 2011 and 2016 as well as from 2017 to 2022. The study examined two-vehicle crashes involving at least one fatality between vehicles one to four years old. For each time period, researchers measured fatality rates by vehicle type and weight.
IIHS noted that technology advancements deployed in newer model SUVs and trucks have led to safer driving conditions for nearby vehicles. Models produced since 2009 have improved “vehicle crash compatibility,” or attributes that protect occupants in the case of a crash, but also occupants of other vehicles.
According to IIHS, between 2011 and 2016, occupants of a smaller vehicle were 90% more likely to die in a crash with a large SUV (weighing 5,000 pounds or more) than in a crash with a smaller vehicle, but only 20% were more likely to perish in a crash with a larger SUV between 2017 and 2022.
However, while improved design of larger vehicles has mitigated fatality risk for drivers of smaller cars, the IIHS concluded that the increasing weight of larger vehicles is still a major threat for other drivers. In addition, improvements like better airbag technology and other new safety features mean that greater vehicle weight does little to benefit drivers of larger vehicles.
The study found that for each additional 500 pounds of a pickup truck that weighed more than the average weight of vehicles in the study (4,000 pounds), the crash death rate of drivers of smaller vehicles rose by seven, while the fatality rate for pickup truck occupants only declined by one.
“What this analysis shows is that choosing an extra-heavy vehicle doesn’t make you any safer, but it makes you a bigger danger to other people,” said Sam Monfort, IIHS senior statistician and lead author of the study.
