By
February 5, 2025
Park a tiny Mini Cooper within the shadow of an enormous Chevrolet Suburban, and it appears apparent which automobile would provide its occupants extra safety in a head-on collision. However there’s a transparent ceiling to the notion that larger is safer, new analysis from the Insurance coverage Institute for Freeway Security exhibits.
For automobiles that weigh lower than the fleet common, the danger that occupants will probably be killed in a crash decreases considerably for each 500 kilos of extra weight. However these advantages prime out shortly. For automobiles that weigh greater than the fleet common, there’s hardly any lower in threat for occupants related to extra poundage.
On the flip aspect, including 500 kilos to a lighter-than-average automobile poses just about no elevated threat to individuals in different automobiles. However the identical weight improve for a heavier-than-average automobile will increase the hazard to individuals in different automobiles.
“For American drivers, the traditional knowledge is that if larger is safer, even larger should be safer nonetheless,” IIHS President David Harkey mentioned. “These outcomes present that isn’t true at the moment. Not for individuals in different automobiles. And — that is essential — not for the occupants of the massive automobiles themselves.”
IIHS has been finding out crash compatibility — or how the interplay between completely different automobiles impacts the relative security of their occupants — for a few years. For this replace, researchers examined two-vehicle crashes that occurred between 1- to 4-year-old automobiles, SUVs and pickups. They checked out two durations, 2011-16 and 2017-22, and calculated driver dying charges for automobiles and their crash companions per million registered automobile years (i.e., one automobile registered for one yr).
Usually, the researchers discovered that compatibility throughout automobile sorts has continued to enhance, a phenomenon that IIHS first documented in 2011 and analyzed most recently in 2019.
For a few years, SUVs and pickups posed an outsize menace to individuals in automobiles, partly as a result of their force-absorbing buildings weren’t aligned. Because of this, when an SUV or pickup struck a automobile, it bypassed the automobile’s crumple zone and rode up over the hood of the smaller automobile.
Starting in 2009, as a part of a voluntary dedication that IIHS helped dealer, automakers modified the entrance ends of their SUVs and pickups to make them align higher with automobiles’ energy-absorbing buildings. Additionally they strengthened the buildings of their automobiles and added aspect airbags to all types of automobiles to guard occupants in T-bone crashes.
Largely on account of these modifications, each SUVs and pickups are considerably much less harmful to individuals in automobiles than they had been earlier.
As a result of the examine checked out 1- to 4-year-old automobiles, some SUVs and pickups within the 2011-16 pattern dated from earlier than automakers modified the construction of their entrance ends. In these years, automobile occupants had been 90% extra more likely to die in crashes with SUVs weighing greater than 5,000 kilos as in crashes with different automobiles. (SUVs of that weight embody most automobiles categorized as large SUVs within the IIHS ranking system.)
In distinction, between 2017 and 2022, these heavy SUVs had been solely 20% extra doubtless than automobiles to lead to car-partner fatalities.
Compatibility improved virtually as a lot for pickups, although they remained harmful to drivers in automobiles.
Pickups had been 2½ occasions as doubtless as automobiles to lead to car-partner fatalities in 2011-16 however rather less than twice as doubtless in 2017-22.
Now that their force-absorbing buildings are higher aligned with these of automobiles, a better share of the danger they pose to crash companions comes from their weight.
Nevertheless, enhancements to airbags and different occupant safety applied sciences imply that the relative security advantages of being inside a bigger SUV or pickup have decreased, the examine exhibits.
The typical weight of passenger automobiles within the examine pattern was 4,000 kilos.
For automobiles under that common, each extra 500 kilos in curb weight decreased the motive force dying fee by 17 deaths per million registered automobile years, whereas solely rising the dying fee for crash-partner automobiles by one.
In distinction, for pickups above the common weight, each extra 500 kilos solely decreased the motive force dying fee by one however elevated the dying fee for crash-partner automobiles by seven.
How added weight impacts driver and crash-partner dying charges per million registered automobile years
Including 500 kilos to automobiles, SUVs and pickups below 4,000 kilos
Including 500 kilos to automobiles, SUVs and pickups over 4,000 kilos
“There’s nothing magical about 4,000 kilos besides that it’s the common weight,” mentioned Sam Monfort, a senior statistician at IIHS and lead writer of the examine. “Autos which might be heavier than common usually tend to crash into automobiles lighter than themselves, whereas the reverse is true for automobiles which might be lighter than common. What this evaluation exhibits is that selecting an extra-heavy automobile doesn’t make you any safer, nevertheless it makes you a much bigger hazard to different individuals.”
In step with that remark, modifications in automobile weights account for a number of the enhancements in compatibility in addition to the continued hole between SUVs and pickups.
The load of the common U.S. automobile elevated to three,308 kilos in 2017-22 from 3,277 kilos within the ancient times, bringing the class nearer to the 4,000-pound all-vehicle common.
As that was taking place, the portion of SUVs weighing greater than 5,000 kilos fell from almost 11% of all late-model SUVs in 2011-16 to 7.4% in 2017-22.
In distinction, pickups bought bigger. The proportion weighing greater than 4,000 kilos elevated to 97% of late-model pickups in 2017-22 from 91% within the ancient times.
“It’s a constructive growth that automobiles and SUVs are actually nearer in weight,” Harkey mentioned. “These numbers present that transitioning to lighter pickups might have massive advantages too, particularly since many drivers don’t use their vehicles for carrying heavy payloads.”
