For about 30 years the Insurance Institute for Highway Safety (IIHS) has focused its moderate overlap frontal crash test on an adult-sized dummy in the front passenger seat. Those tests exceeded legal requirements and helped drive big improvements in front-seat protection: better crumple zones, smarter restraints and safer cabin designs.
As front-seat safety improved, real-world crash data showed an unexpected consequence: people seated in the back were becoming relatively more vulnerable. IIHS analysis found the fatality risk for rear-seat occupants was about 46% higher than for comparable front-seat occupants. Senior IIHS vehicle researcher Jessica Jermakian says the field data made it clear the back seat had not kept up with advances up front.
IIHS continues to recommend that young children ride in the back because of airbag risks, but for belted teens and adults — and with more adults riding rear seats for ridesharing and other reasons — the back seat is now comparatively riskier. To address that gap, IIHS added a child-sized dummy to the rear seat in 2022 and further tightened its moderate overlap frontal test in 2024.
The upgraded test can be dramatic. At an IIHS facility in Virginia, a Subaru Crosstrek was driven into a barrier at 40 mph with an adult dummy in the front and a 12-year-old-size dummy in the rear. The crash forces flung the child dummy’s hand out through the rear window, a scene that visibly alarmed observers and underscored the stakes of rear-seat protection.
The tougher criteria exposed problems fast. Under the revised ratings, about 20% fewer vehicles earned IIHS safety awards. Even vehicles long marketed for family use lost ground: no minivan met the Top Safety Pick standard in 2025, largely because of weak rear-seat performance.
Some manufacturers moved quickly. The Hyundai Sonata, for example, scored poorly on the updated moderate overlap test in 2023 because the rear-seat dummy showed likely head/neck, chest and abdominal injuries while the driver dummy remained well protected. Hyundai responded by adding rear-seat pretensioners (which tighten belts immediately in a crash), force limiters (which allow controlled belt payout later in a crash), and strengthening side structure around rear occupants. By 2025, the Sonata earned the highest rating on that revised test. Hyundai’s safety leaders say the changes reflect a rapid, targeted response to the new requirements.
IIHS media staff and researchers say that similar improvements have appeared across other models. Jermakian notes that upgrading rear-seat belts is an effective change automakers can implement relatively quickly; some manufacturers are also considering more extensive redesigns, such as reshaping rear seats and enhancing rear-seat anchorage and structure.
From IIHS’s perspective, a wave of failures after raising the bar is partly a sign the test is doing its job. When nearly every vehicle aces a given assessment, the test loses effectiveness as an incentive for further safety gains. By tightening the moderate overlap frontal test and adding rear dummies, IIHS aims to push automakers to bring rear-seat protection closer to the high level front-seat occupants now enjoy.
The result should be safer rides for teens and adults who travel in the back, and better protection for families overall as automakers adopt belt upgrades, structural reinforcements and seat design changes that address the vulnerabilities revealed by the new testing protocols.