Vehicle Safety Ratings, Crash Test Ratings, and How They Work

You have many factors to consider when choosing your next new vehicle. Price is often the primary one because you’re on a budget. Reliability is another since you want to get the most for your money. Safety represents another vital factor in your decision as to what vehicle to buy.

Read our guide to vehicle safety ratings, crash test ratings, and how they work to learn more about what goes into these numbers. We’ll take a closer look at National Highway Traffic Safety Administration (NHTSA) safety ratings as well as the Insurance Institute for Highway Safety (IIHS) ratings.

What Are Vehicle Safety Ratings?

Vehicle safety ratings assess a car’s ability to protect occupants during crashes and avoid accidents. Independent experts conduct rigorous tests that simulate major accidents, including frontal, side, and rollover situations, to evaluate the structural integrity and safety features in cars, trucks, and SUVs. 

These ratings provide a standardized way to compare vehicles, helping you make informed decisions as to what vehicles are the safest when selecting a car. Higher-rated vehicles often include advanced safety technologies, such as automatic emergency braking and lane-keeping assist. 

Two major organizations in the United States compile vehicle safety ratings for car shoppers to examine. The National Highway Traffic Safety Administration (NHTSA) simulates three crash types and assesses a vehicle’s safety features, creating individual ratings for each test and a final rating that combines all three tests. The Insurance Institute for Highway Safety (IIHS) has five basic crash tests, including the strength of the roof and testing for seatbelts. 

NHTSA Vehicle Safety Ratings

The NHTSA does not test all new vehicles that come out. Some vehicles have low sales, and some brands do not undergo testing. While other organizations test for crashworthiness, the NHTSA is notable in that it’s the only organization that rates rollover resistance. Rollover resistance is how well a vehicle resists rolling over during a collision.

How the NHTSA Selects Vehicles for Testing

The agency selects vehicles based on market popularity and new model introductions. NHTSA prioritizes testing vehicles likely to sell in high volumes, ensuring the results impact a significant number of consumers. The agency also includes models with redesigned structures or added safety features to verify that changes improve protection for a vehicle’s occupants. 

In an update for 2024, the NHTSA will evaluate four more advanced driver assistance technologies and assess how a vehicle’s front end can mitigate pedestrian injuries.

There are several independent labs across the United States that create unbiased reports on each vehicle. If a vehicle has a history of consumer complaints or potential safety issues, the NHTSA may choose to test or re-test certain vehicles. These re-tests can change the final ratings given to a vehicle.

For example, the GMC Yukon has been around since 1992. It’s in the middle of its fifth generation and underwent a refresh for the 2025 model year that added new safety features like a night-vision camera. Therefore, the NHTSA would test this SUV. However, if there isn’t much change from one model year to the next, the NHTSA may refrain from testing. This method ensures that ratings reflect the latest automotive advancements and provide buyers with relevant safety information. 

Simulating Crashes at the NHTSA Laboratory

To simulate crashes, the NHTSA conducts four primary tests: frontal crash, side-impact, side-pole, and rollover resistance. 

The frontal crash test involves a head-on collision at 35 mph against a fixed barrier, representing typical accidents at intersections or when one vehicle passes another on a two-lane, two-direction highway. Engineers measure the impact on crash test dummies seated and seatbelted in the driver and front passenger positions to gauge injury risk. 

Side-impact tests evaluate protection during collisions where another vehicle strikes the side at 38.5 mph, commonly known as a “T-bone” collision. A moving barrier weighing 3,015 pounds strikes the side of the test vehicle to simulate the collision. The vehicle itself remains stationary. One crash test dummy sits in the driver’s seat and another in the seat behind the driver. The crash test dummies are slightly different in size, one simulating the average size of an adult male and the other the average size of an adult female.

The side-pole crash test simulates a vehicle hitting a tree or utility pole at 20 mph at a 75-degree angle. One crash test dummy sits in the driver’s seat to assess how hitting the 9.5-inch-diameter pole affects the driver.

Rollover resistance tests do not physically use a crash test dummy. Engineers calculate the vehicle’s stability based on center-of-gravity measurements, the vehicle’s suspension, and dynamic handling performance during sharp turns. These measurements derive the Static Stability Factor. In addition to the star rating for a vehicle, the NHTSA shows a rollover risk percentage. For example, a vehicle with a rollover risk of 21% would have a 21% chance of rolling over in a single-vehicle crash. The lower the percentage, the better. Rollover resistance does NOT factor into crashes that involve multiple vehicles. 

Each of the three simulated tests generates data from sensors embedded in crash test dummies. Highly sophisticated sensors and cameras record the impact forces, the movement of the vehicle and its components, and the response of the crash test dummies. Measurements taken during the crashes include head impacts, chest impacts, and the deformation of the vehicle’s structure. The data is compiled to record the forces generated during the simulated accident, accelerations, and potential injuries. 

Analysts process this data to evaluate the effectiveness of seat belts, airbags, and crumple zones. 

Key factors that engineers pay the most attention to are these three:

1. The level of intrusion into the passenger compartment.
2. The forces experienced by the crash test dummies.
3. The effectiveness of airbags and other safety features in mitigating injuries.

What Do the Crash Test Ratings from the NHTSA Say?

The NHTSA vehicle safety ratings use a five-star system, where more stars indicate higher safety performance. A vehicle with five stars performs exceptionally in all tested categories, offering robust protection for occupants. Lower ratings signal areas where the vehicle may expose passengers to higher risks during crashes. The system enables easy comparison across different models, empowering consumers to choose cars that align with their safety priorities.

More stars generally mean safer cars:

• 5 Stars: Highest level of safety.   
• 4 Stars: Very good level of safety.
• 3 Stars: Acceptable level of safety.
• 2 Stars: Marginal level of safety.
• 1 Star: Lowest level of safety.

When looking at the crash test for the side crashes, they are evaluated separately and as an overall side rating.

Examining New Advanced Safety Features

In addition to crashworthiness, NHTSA evaluates advanced driver-assistance systems (ADAS), such as forward collision warnings and lane-keeping assist. Engineers test these systems under various conditions to determine their effectiveness in preventing accidents. Vehicles with highly effective ADAS receive recognition for reducing crash risks.

The NHTSA lists whether each vehicle has standard or optional advanced safety features with four recommended advanced safety technologies:

• Forward collision warning
• Lane departure warning
• Crash imminent braking
• Dynamic brake support

The NHTSA notes whether these features meet the agency’s performance criteria.

As part of the 2024 expansion into other advanced driver assistance technologies, the NHTSA will evaluate the following in addition to the four already mentioned:

• Pedestrian automatic emergency braking
• Lane-keeping assist
• Blind spot warning
• Blind spot intervention

IIHS Vehicle Safety Ratings

The goal of the Insurance Institute for Highway Safety (IIHS) is to make roads and vehicles safer for everyone. It’s an independent, nonprofit scientific and educational organization dedicated to the research and evaluation of vehicle and road safety. Part of its mission revolves around testing vehicles for safety.

The IIHS takes a similar approach to the NHTSA by conducting detailed crash tests and assessing crash avoidance systems. Its ratings are a bit different from those of the NHTSA, but the outcome is the same. IIHS helps consumers identify cars that protect occupants effectively and minimize accident risks. Like the NHTSA, the IIHS may re-test certain vehicles and change the ratings based on the second test.

How the IIHS Selects Vehicles for Testing

Vehicles selected for testing by the IIHS usually represent popular models, new releases, or redesigns with updated safety features. As part of the IIHS’s independence, it purchases vehicles anonymously from a dealership rather than having vehicles sent to the organization by the manufacturers.

In addition to bestselling vehicles, the IIHS also includes smaller-volume models with unique safety claims, ensuring comprehensive coverage of the automotive market. 

What Crash Tests Does the IIHS Perform?

The IIHS performs five primary crashworthiness tests to simulate real-world accident scenarios. 

• The small overlap front test has a portion of the vehicle’s front end strike a barrier at 40 mph, mimicking collisions with poles or trees. 
• The moderate overlap front test involves a broader frontal impact at the same speed, simulating head-on crashes. 
• The side-impact test evaluates occupant protection when struck by another vehicle traveling at 31 mph. 
• Additionally, the IIHS tests roof strength by pressing a metal plate onto the roof to assess its ability to withstand rollover forces. 
• Finally, engineers measure head restraint and seat performance to determine protection against whiplash during rear-end collisions.

Crashworthiness tests rely on sensors embedded in crash test dummies to record data on forces, acceleration, sudden movements and changes of direction, and potential injuries during simulated impacts. Engineers analyze the structural deformation of the vehicle’s cabin, the effectiveness of crumple zones, and the performance of airbags and seatbelts. 

In addition to crash tests, the IIHS evaluates crash avoidance and mitigation systems. Engineers test features such as forward collision warning, automatic emergency braking, and pedestrian detection under controlled conditions to see if these systems perform as expected. 

The IIHS also examines headlights, an often-overlooked safety component. Tests measure visibility at night and assess glare control to ensure drivers can see clearly without blinding others. Advanced safety features such as auto high beams and adaptive headlights on vehicles are noted.

What Do the Crash Test Ratings from the IIHS Say?

Rather than rating vehicles with one to five stars like the NHTSA, the IIHS determines if various tests receive a Good, Acceptable, Marginal, or Poor rating. These ratings are color-coded. When evaluating safety features like headlights and seatbelts, these items receive Superior, Advanced, or Basic ratings with one to three green bars filled in (similar to cellphone signal strength bars).

Vehicles with effective systems receive recognition for their contribution to road safety. The IIHS does more than just have a rating system for vehicles. Evaluators comment on the factors that led to the decisions, such as how an advanced safety technology performed during testing.

The IIHS awards vehicles with outstanding performance in crash tests and safety features with honors such as Top Safety Pick or Top Safety Pick+. These awards signify that a vehicle excels in protecting occupants, avoiding accidents, and ensuring visibility at night. Most award winners have a suite of advanced safety features that perform as expected or better than expected.

When Do Vehicle Safety Ratings Come Out?

There is no set time for either the NHTSA or IIHS to reveal vehicle safety ratings. Both organizations test vehicles throughout the year. Because automakers do not release new vehicles at the same time every year, not all models receive updates every year, and vehicle ratings do not come out every year at specified times.

However, the IIHS does compile its Top Safety Pick and Top Safety Pick+ selections by model year. These lists can change as new vehicles are added.

Vehicle Safety Ratings of New Models at Thompson’s

Now, we’ll dive into the safety ratings for new vehicles at Thompson Sales for both the NHTSA and IIHS. You can click on the links to both organizations to view the vehicle safety ratings in detail. On each page for the individual ratings, you can see detailed technical reports of what engineers found out.

Buick

The Buick Envista, the manufacturer’s smallest and newest SUV, received four stars from the NHTSA. When evaluated by the IIHS, the Envista received Good marks for the original front tests followed by Acceptable for the side tests. Most standard safety features are Acceptable.

The Buick Encore GX has been a stalwart of the brand for over 10 years. As such, it’s one of Buick’s safest SUVs, and it has a five-star rating from the NHTSA. This vehicle earned Good marks for the crash tests from IIHS and Superior marks for front crash prevention. 

The Buick Envision has more space than the Encore GX, and has been in its current generation since 2020. The Envision earns a high mark of five stars from the NHTSA and then Good marks on all of its crash test results from IIHS.

The largest and most luxurious SUV from Buick is the three-row Enclave.  It received an overall five-star rating from the NHTSA, followed by Good or Acceptable marks from the IIHS.

GMC SUVs

Our selection of GMC SUVs stands apart from others with their premium features and stout engines.

The GMC Terrain is the smallest SUV in the lineup and one of our most popular selections for the premium features and all-wheel-drive powertrain option. It received a five-star rating from the NHTSA, and it has mostly good ratings for crash tests from the IIHS.

The GMC Acadia is a midsize SUV with a long history of excellent safety ratings. It received five stars from NHTSA and mostly Good ratings from the IIHS.

The GMC Yukon and Yukon XL are the largest mainstream SUVs from the manufacturer. Both have three rows of seating, while the Yukon XL has a longer wheelbase and more cargo space behind the third row. The Yukon and Yukon XL both received four stars from the NHTSA. Meanwhile, these vehicles were not tested by the IIHS.

GMC Trucks

GMC pickup trucks are some of our bestselling models and with good reasons. They have stout engines, premium cabins that serve as mobile offices at job sites and when managing your acreage, and world-class towing capabilities and towing technology.

The GMC Canyon is designed for light-duty tasks and fun weekend getaways. The NHTSA rated the Canyon at four stars. The IIHS rated the crew cab configuration with mostly Good marks. 

The GMC Sierra 1500 is a full-size, light-duty truck with towing capabilities north of 10,000 pounds for some trims.  The extended cab version achieved a five-star rating from NHTSA, and it has mostly Good or Acceptable ratings from the IIHS.

GMC Sierra HD heavy-duty pickups come in 2500 or 3500 models. The 3500 has the top towing figure of over 30,000 pounds for fifth-wheel trailers. The GMC Sierra 2500 was last evaluated in 2019 by the NHTSA and earned four stars. None of the other models in this lineup have been rated by either organization.

Test-Drive a Safe New or Used Vehicle in Springfield, MO

If you’re ready to get started with in-person evaluations of your next vehicle, we can point you to the safest new or used vehicles on our lot. Contact us, call (417) 763-6811, or schedule a test drive with our team. We’re happy to help in any way we can!