Side Impact Crash Testing: What the Numbers Really Mean

While vehicles have become much safer than they were even ten years ago, one fact remains the same. As far as safety is concerned, not all vehicles are created equal. Consumers almost automatically turn to crash test ratings to ;earn more about a vehicle they may be interested in. But, do we really understand how these word? There are two agencies that test new vehicles and publish scores rating the cars on various types of crash situations. The National Highway Traffic Safety Administration (NHTSA) and the Insurance Institute for Highway Safety (IIHS) both began looking at automobile safety in the 1960s when the public became more aware of the issue. The first crash tests were conducted by NHTSA, which is a division of the Department of Transportation, in 1978. The IIHS, which is supported by automobile insurance companies, didn’t begin its crash testing for consumers until 1995.

Understanding Side-Impact Tests

As with the frontal tests, the side-impact tests that the two groups conduct are also quite different. Both tests simulate the type of side collision that would typically occur in an intersection, by crashing a deformable barrier into the vehicle being tested. In the NHTSA test, two dummies that represent average-sized men are placed in the driver seat and in the rear, directly behind the driver. A 3,015-pound barrier is then slammed into the vehicle at 38.5 mph. The force of the impact to the dummies’ head, neck, chest and pelvis is measured, but star ratings indicate only the chance of serious injury to the chest. Head injuries, which are not included in the star rating, are reported separately as what NHTSA calls a “safety concern” if the likelihood of head injuries is considered excessive.

The IIHS test differs from the government test in the type of barrier that is used, the size of the dummies placed in the vehicle and what the test measures. Using a “Good” to “Poor” rating system, the group measures the potential of injury to the head, neck, chest, abdomen, pelvis and femur, and gives a rating based on the performance in all of these areas. The IIHS uses two dummies that represent small women or 12-year-old children (5 feet tall and 110 pounds) and places them in the driver seat and in the rear seat behind the driver.
In addition, the IIHS’s barrier has a different shape and weighs more. The group uses a 3,300-pound deformable barrier that is taller and is shaped like the front of a pickup or SUV that is propelled into the side of the test vehicle at 31 mph. The Institute’s test is so severe, in fact, that it is unlikely people who experienced such a crash in the real world would come away free of injuries. The group looks for side-impact protection that allows the occupants to survive these types of crashes without serious injury.