Purchasing a Car: Understanding Vehicle Safety Crash Ratings

First of all, just because your vehicle is on a “Top Ten Safe Vehicles” list, don’t think that makes it safe. Although all vehicles on the market in the U.S must comply with the minimum safety standards and performance requirements set forth in the Federal Motor Vehicle Safety Standards (FMVSS), many experts consider these standards to be inadequate. However, there are a number of testing organizations, both government and private, that perform crash tests on motor vehicles and issue safety ratings.

Two of the most commonly used crash evaluations are the ratings from the Insurance Institute for Highway Safety (IIHS) and the ratings from the New Car Assessment Program (NCAP) which is part of the U. S. Department of Transportation’s National Highway Traffic Safety Administration (NHTSA). While both organizations have an interest in educating consumers about the crashworthiness of the vehicles they test, the evaluation methods each one uses are quite different.

The New Car Assessment Program (NCAP) is a government-run program which grades its crash test results on a rating system of 1 to 5 stars, with 5 being the highest or best (10% or less chance of serious injury) to 1 being the lowest or worst (46% or greater chance of serious injury). The NCAP agency does not rate all vehicles, however, and primarily chooses those new vehicles which are predicted to be big sellers. The agency buys its test vehicles directly from dealerships across the country; significantly, the vehicles are not supplied by the manufacturers. (1) NCAP does not use rear impact crash results in their evaluation or rating, in part because they have a limited budget, and also because front and side-impact crashes are responsible for the highest percentage of deaths and serious injuries.

The Insurance Institute for Highway Safety (IIHS) program is an independent, nonprofit organization supported by insurance companies. (2) Their scientific safety tests include evaluations of frontal impacts based on 40 mph impacts, side crashes involving a vehicle being struck by a barrier moving 31 mph, and rear crashes based on impacts at 20 mph. Recently, IIHS started including test results for rollover crashes with the roof strength tests. Their evaluations are conveyed with results of “poor”, “marginal”, “acceptable”, or “good”. In order to make the top safety picks, a vehicle must have a “good” rating in all four tests (front, side, rear, and rollover).

Sometimes the ratings by these two organizations of the same vehicle can be very different. The different ratings can be due to the methodologies used and the way the tests are conducted. For instance, the NCAP front impact tests are conducted by crashing the vehicle head-on into a flat solid barrier, while the IIHS front impact tests are performed by crashing a vehicle head-on into a barrier that is primarily on the driver’s side and is deformable. (3) Many experts believe the IIHS test is more realistic because it simulates the impact in a crash between two vehicles traveling in the opposite direction where one vehicle crosses the center line and strikes the other vehicle head-on but primarily on the driver’s side. This type of impact occurs more often in real collisions, and puts more stress on the driver’s side of the car. As a result of the different testing methodologies, sometimes there are significant differences in the ratings results. For instance, recently the Kia Spectra received a “poor” rating in front impact crash testing by the IIHS. This was the first time since 2001 that the IIHS had given such a bad rating to a car. Surprisingly, the Kia Spectra had received 4 out of 5 stars by the NCAP/NHTSA in front impact crash ratings. (4)

As an automotive consumer, when you are considering a car and interested in its safety, spend some time and research a number of different ratings organizations on the vehicle you are interested in. Keep in mind that you also want a car that is comfortable for you. Some vehicles seem to be designed for and are more comfortable for tall drivers, others for shorter drivers, and some for drivers with longer legs but shorter trunk, or drivers with shorter legs but a longer trunk, and so on. Find a vehicle that is comfortable for you to drive and handles well for you.

In summary, be an informed consumer and consider your purchase carefully, with safety as an important consideration in your decision. And think about safety not only when you are deciding on which vehicle to purchase – but also when you are driving! Remember that most accidents are caused by carelessness and driver inattention. Think safety!

About the author: Kathleen Smith is a Fredericksburg car accident attorney.


(1) See http://www.iihs.org/news/rss/pr111809.html.

(2) See http://www.safercar.gov/portal/site/safercar/menuitem.13dd5c887c7e1358fefe0a2f35a67789/?vgnextoid=b2c72d0e0c2c8110VgnVCM1000002fd17898RCRD

(3) “Deformable” means the barrier collapses some, like another vehicle would if you crashed into it, whereas the NCAP test barrier is solid. See IIHS test protocols at http://www.iihs.org/ratings/protocols/pdf/test_protocol_high.pdf.

(4) See http://www.automobile.com/good-nhtsa-and-poor-iihs-kia-spectra-ratings-raises-questions-about-crash-test-methods.html.