Understanding Crash Test Safety Ratings

Car Crash Test

Crash Tests – Insurance Institute for Highway Safety

Buying a new or used vehicle has become a research intensive proposition. Not only do you need to know if the vehicle fits your lifestyle, if you like it’s design and other personal choices, but many consumers also want to know a vehicle’s mileage efficiency and now more than ever a car’s crash test safety ratings.

However, with two different agencies conducting different tests, it seems confusing. Yet as one of the most important aspect to buying a new car, learning to research and understand these different rating systems is important. In this article the National Highway Traffic Safety Administration (NHTSA) and the Insurance Institute for Highway Safety (IIHS) crash tests will be explained, giving you an overall understanding of this critical buying decision criterion.

NHTSA – 5 Star Safety Ratings

One of the most confusing issues for consumers is the simple fact there are 2 traffic safety crash testing institutions in the US. However, both complete different tests and neither conduct tests on every model produced every year by manufacturers.

The NHTSA is a government agency designed to ensure highway safety for the public at large. Their 5 Star Safety Ratings system is meant to provide clear indications for consumers about the best cars in each segment when making buying decisions. These ratings also serve as notice to manufacturers for models that perform poorly on the tests. Giving feedback to manufacturers in order to enhance their vehicles is a major advantage of both institutions.


The Crash test system for the NHTSA is actually part of the agency’s New Car Assessment Program (NCAP) and is meant to provide consumers with more information about cars and how they perform in crash and rollover tests beyond what is actually required by Federal law. The NCAP conducted by the NHTSA provides their results on the website safercar.gov.

5 Star Ratings

The NHTSA provides a number of crash tests and additional information for consumers in order to make an informed decision. The crash tests of the NHTSA are rated on a sliding scale of 1 star to 5 stars, and thus are called the 5 Star Safety Ratings. These ratings are given on each test performed and so a vehicle could receive multiple evaluations ranging from 1 star to 5 stars on different tests.

Tests Performed

The NHTSA program performs 4 crash tests. The frontal crash test evaluates the vehicle in a head-on full frontal collision with a vehicle of the same weight class. This test uses two different sized dummies, representing average male and female sizes measuring possible injury during the test. The frontal crash test is only meant to be comparable among vehicles that are within 250 pounds gross weight of each other.

The side pole crash test evaluates the vehicle on a side impact with the use of a narrow pole; like crashing into a tree or light pole. This test is comparable across all vehicles because it uses the same size and pole weight.

The side barrier crash test uses a wide barrier as if the car was struck by another vehicle. The same size and weight barrier is used allowing for easy comparison across all vehicles.

The fishhook rollover test uses an s-curve driving pattern to test how easy a car will rollover at a certain speed. As rollovers have a higher percentage of fatalities it provides a good indication of safety against this type of crash.

These four tests give a pretty good overall indication of the safety of a vehicle in some of the most popular crashes on highways in America. The NHTSA does not specifically rate safety technologies such as Forward Collision Warning or Lane Departure Warnings but does provide recommended technologies in its ratings. These recommendations help a consumer understand that having certain technologies can help in better safety according to the NHTSA’s tests. However, the IIHS also provides a number of crashes as well in addition to the NHTSA.

IIHS – Top Safety Pick & TSP+

The IIHS is not a federal agency of the US government. In fact it is a non-profit organization that is funded mainly by the insurance industry to provide a better understanding of crash test information. This information can be used to better performance of crash avoidance and mitigation technologies and helps insurance companies reward buyers with “safer” cars.

The IIHS names their program as the Top Safety Pick and the Top Safety Pick Plus ratings. However, their safety ratings programs take into account both the crash-worthiness of a vehicle as well as the modern safety crash avoidance and mitigation technology.

Crash Prevention Ratings

The IIHS realized since 2013 that the crash avoidance, mitigation and prevention technologies were actually helping do what they intended; reduce the severity of crashes. In an attempt to help consumers understand this, they provided another tier in their ratings programs called the TSP+, denoting that the vehicle not only meets the crash-worthiness standards, but in fact actually helps to avoid or reduce crashes altogether.

The new ratings are assessed to vehicles in a Basic, Advanced and Superior rating system that also determines whether a model will be awarded the coveted TSP+ award. Not all vehicles include these top safety features, so the IIHS’ system really does help to weed out the top contenders for the safety conscious buyer.

Five Crash-type Tests

The IIHS conducts 5 tests that are different from the NHTSA. They do two frontal crash tests, but conduct a moderate overlap and small overlap frontal crash test configurations. These tests are meant to test the vehicle’s response to a frontal crash that is not a full head-on collision, as many front crashes only strike a portion of the front of the car. The small overlap test has been very good at distinguishing how a corner impact is especially damaging to some car designs.

The side crash test of the IIHS also differs from NHTSA by the fact that its full side barrier mimics that of a pickup truck or SUV providing a better understanding of crash safety against a larger vehicle.

The roof strength test considers the safety of the occupants should a vehicle actually rollover. Where the NHTSA tests if a vehicle rolls over, the IIHS has focused on how a vehicle will stand up to a roll over should it do so. Low scores for both tests proves a low incidence of rollover and a low incidence of injury, should a vehicle do so.

Lastly the IIHS tests the safety of head restraints and seat safety during the crash tests. These tests help provide valuable insight into head restraints ability to protect your most vulnerable body part and determine the safety that the seat of the vehicle provides.


The IIHS safety ratings show up in 2 forms. The TSP designation means that the vehicle has received a good rating in all tests and at least an acceptable in the small overlap test. Whereas the TSP+ designation meets the TSP standards and earned an Advanced or Superior rating in the crash prevention technologies portion of the review of the vehicle.

The IIHS tests are just as important as the NHTSA tests, and the fact that the two do not test the same safety areas, provides a more complete picture, especially with the limited funding that both organizations work with.

Determining Safe Vehicles

Finding the safest car is easy, now that these organizations provide their results online for consumers to look at.

Simply go to safercar.org or the IIHS’s Ratings list to see all the vehicles that have top safety ratings. The NHTSA provides crash test ratings as far back as 1990 whereas the IIHS provides ratings since 2006. The NHTSA provides an easy lookup feature on their database with a comparison module for easier comparisons. The IIHS breaks down their ratings into vehicle segments and by year to provide a quick reference for safety ratings.

Being able to research both safety ratings from these important testing organizations is important for new and used car buyers. If you have a choice between 2 vehicles that meet your need, are roughly the same price, but one is a Top Safety Pick or has a 5 Star Crash Test Rating, your decision should be easy.

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