The introduction of the driver front airbag has been a game-changer in vehicle safety, dramatically reducing the risk of fatal injuries in frontal crashes. Since 1979, NHTSA’s full-frontal crash test has been a key measure of vehicle restraint system effectiveness, particularly focusing on seat belts and airbags. Over the years, we’ve seen substantial improvements in vehicle safety as airbags became more common. But just how much did a car’s safety performance improve when a driver airbag was added?
For this analysis, I looked at 44 vehicle models that NHTSA tested both with and without a driver airbag. These models were selected because their airbag versions didn’t undergo a major redesign, ensuring the non-airbag and airbag versions were structurally similar.
The findings were striking: On average, adding a driver airbag reduced the risk of serious injury for the driver from 30% to 18%. This means that 40% of people who would have suffered severe injuries with just a seatbelt were protected from serious harm thanks to both the seatbelt and the airbag. Statistically, this is a significant improvement, showing a 90% confidence level, and clearly demonstrates the life-saving potential of even the earliest airbag systems.
Out of the 44 vehicles tested, 33 showed a reduction in injury risk, 1 remained unchanged, and 10 had slightly higher injury risks with the airbag. However, in 7 of these 10 cases, the increase was less than 5%, and these vehicles had already performed well in tests without airbags. On the other hand, 10 cars saw a dramatic reduction of at least 20% in injury risk.
Looking at NHTSA’s 5-star rating system, where 3 stars or more is considered “passing,” 30 of the 44 non-airbag vehicles passed, meaning nearly a third failed. However, of the 44 vehicles equipped with airbags, 41 passed, with failure being an exceptionally rare occurrence. Only 2 of the airbag-equipped cars failed, and they were borderline cases.
The most significant takeaway? The addition of driver airbags nearly eliminated the most dangerous vehicles in the tests.
Interestingly, the benefits of airbags were even more pronounced for trucks, vans, and SUVs. While cars saw an average injury risk reduction from 25% to 15%, trucks, vans, and SUVs experienced a more substantial decrease from 37% to 22%.
Further analysis revealed even better news for airbags. The Head Injury Criterion (HIC), which measures head injury risk, dropped by 35% on average, from 974 to 636. The upper body G-forces decreased from 49.7 to 49.4, showing a less than 1% improvement.
For cars, the HIC dropped by 32% from 880 to 595, and chest G-forces decreased by just 1%, from 47.5 to 47.0. Trucks, vans, and SUVs saw the most significant improvement, with the HIC dropping by 37% from 1,086 to 686, though chest G-forces remained unchanged at 52.4.
Breast compression, which correlates more closely with severe injury risk than chest G-forces, became the primary injury measurement in 2011, adopted by NHTSA and IIHS. While chest G-forces are typically only dangerous at very high levels, HIC remains the gold standard for measuring head injury risk worldwide. This suggests that the reduction in severe injury risks was likely even greater than the percentages indicate, as most of the improvements were in head injury protection.
Furthermore, airbags help distribute the forces of the crash over a larger area of the body, reducing the likelihood of localized injuries such as facial fractures. In vehicles without airbags, even the safest models, the dummy’s head typically hit the steering wheel during the crash. In contrast, with airbags, an actual person would be much better protected, as the airbag helps cushion the blow and spread the impact across the body.
In summary, the addition of driver airbags has significantly improved vehicle safety, reducing the risk of severe injury and saving countless lives. Whether in cars, trucks, vans, or SUVs, airbags have proven to be one of the most effective safety features on the road.
