Of all the things IIHS rates, this is the one that sounds least like safety engineering. It measures whether the car makes enough noise when somebody is not belted.
The reasoning is straightforward. Belts are the most effective occupant protection ever fitted to a car, and a substantial share of people killed in crashes were not wearing one. Every other safety system has to work around that failure. A reminder is the only one that prevents it.
The evaluation sets a minimum: how loud, how long, and — the part most cars failed — whether the rear seats are covered at all.
| Model year | Rated | Poor or Marginal | Share |
|---|---|---|---|
| 2022 | 67 | 44 | 66% |
| 2023 | 93 | 34 | 37% |
| 2024 | 115 | 25 | 22% |
| 2025 | 143 | 27 | 19% |
| 2026 | 129 | 23 | 18% |
Two thirds of the first cars evaluated came back Poor or Marginal. Four model years later it is under one in five.
The back seat is where almost all the failures were
Nearly every car has managed a front seat belt chime for decades. It is required, and it is trivial: one sensor in the buckle, one in the seat.
The rear seats were the gap. A driver who cannot see whether a passenger behind them is belted has no way of knowing, and until this rating existed most cars offered nothing — no chime, no indicator, no display.
That is the specific failure behind most of the 2022 results, and adding a rear indicator is one of the cheapest fixes available to a manufacturer. Which is exactly why the numbers moved so fast.
Cheap tests get fixed fastest
Two patterns are now visible across every rating we have looked at, and they are the same pattern.
Head restraints went from 88% failing to zero because the fix was geometry. Headlights halved in four years because the fix was a better lamp. Belt reminders collapsed from 66% to 18% because the fix is a sensor and a speaker.
Compare that with automatic braking, still failing in one car in five, where the fix requires new sensors and new software. The industry does not respond to severity. It responds to cost.
What it means in the car you own
If your car does not tell you about the back seats, that is not a defect and nothing is broken. It reflects when it was designed.
It also means the check is yours. The occupant most likely to be unbelted is the one nobody can see, and on a car built before this rating existed there is no system watching for it at all.
Frequently asked questions
Is there really a safety rating for the seat belt chime?
Yes. IIHS evaluates whether the reminder is loud enough, lasts long enough, and covers the rear seats. It exists because belts are the most effective protection in the car and a large share of people killed in crashes were unbelted.
Why did so many cars fail it at first?
Almost entirely because of the rear seats. Front seat chimes have been standard for decades, but until this rating existed most cars gave the driver no indication whether rear passengers were belted. Two thirds of 2022 vehicles rated Poor or Marginal; by 2026 it was 18%.
Why do some safety ratings improve faster than others?
Cost, not severity. Fixes that are cheap — head restraint geometry, better headlamps, a sensor and a speaker — get adopted within a few model years. Fixes requiring new sensors and software, like automatic braking performance, move far more slowly.
Denis Kataev is a serial solopreneur and the founder of ForCar. With 15+ years in software engineering and 10 years in SEO, he builds data-driven products end to end — backed by a sharp eye for design. At ForCar he mines proprietary vehicle datasets, turning raw numbers into buying advice you can actually trust.
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