What are car safety ratings?

Airbags and other restraint systems are standard measures to protect drivers and passengers, but they don’t provide the same level of protection since each vehicle performs differently in a crash.

Understanding car safety ratings and how vehicles compare can significantly change your perception of a vehicle and influence your buying decision. Let's explore the differences in car safety ratings, how they work, and how to check them.

Why does a car safety rating matter?

A higher car safety rating means that a car is designed with safety features that tend to protect its occupants better. Put simply, the higher the car safety rating, the lower the likelihood and severity of injuries in the event of an accident.

Naturally, this can make your trips more peaceful, as you can shift focus to enjoying your drive instead of doubting the safety of your car.

The importance of understanding vehicle safety ratings

Car safety rating scores result from rigorous tests that simulate different real-world scenarios on the road.

For instance, frontal crash tests typically simulate head-on collisions. Their results indicate how well the vehicle’s structure absorbs and distributes crash forces and the effectiveness of the seat belts and airbags in protecting car occupants. Therefore, the vehicle’s score in a frontal crash test can help assess the likelihood of a severe injury (that requires hospitalization), allowing you to determine whether it’s a good choice.

Why you should check the safety ratings before buying a car

Once, many believed that larger cars were inherently safer, but this is no longer true. A car's safety depends on various factors and the decisions made during its development phase.

A prime example is the difference in car safety ratings between the Suzuki Swift and the Jeep Wrangler. Euro NCAP tests have revealed that the smaller and less expensive Suzuki hatchback is safer than the Wrangler in all tested categories.

The Swift has demonstrated better protection for adults, children, and pedestrians, illustrating that the size of a vehicle should not be a defining factor in car crash safety. Moreover, the Swift’s driving aids have received higher scores, indicating that, in comparable real-life scenarios, the Swift is safer than the Wrangler.

How to check car safety ratings

You can easily check the car safety rating for every vehicle sold across the UK. Several methods are available, and they’re all too easy to ignore when buying a car.

Get a vehicle history report

It’s a good idea to get a vehicle history report before shaking hands with the seller, and not only because it can help you quickly check the car safety rating.

Vehicle history reports also include other information about a car and its past that is not always obvious but crucial to know, such as damage and mileage records, financial information, title checks, historical photos, and more.

If vehicle safety information is available, the report will show you an overall car safety rating, and the results for specific tested areas (e.g., frontal crash, side crash, and rollover).

Check official safety organizations' websites (like Euro NCAP, ANCAP)

Another way to check a car's safety rating is to visit the NHTSA, IIHS, Euro NCAP, or ANCAP websites (depending on your vehicle's country of origin). You’ll typically need to provide the make, model year, or similar details. Rarer models may not have safety scores due to limited crash testing.

Use trusted automotive resources

Automotive websites like Auto Express, Autocar, Car Magazine, Parkers, and What Car? often review vehicles and report on their safety ratings and breakthroughs in safety technology.

These leading automotive outlets always provide reviews for new and used vehicles, including passenger cars, SUVs, and luxury vehicles. Therefore, you can access detailed information about vehicle features, specifications, pricing, and safety performance, which can help make a better purchase decision.

How are car safety ratings determined?

In the US, car safety ratings are determined by two organizations:

• National Highway Traffic Safety Administration, widely known as NHTSA. It’s a federal agency within the Department of Transportation focused on transportation safety in the United States.
• Insurance Institute for Highway Safety (IIHS), which is a non-profit organization funded by insurance companies dedicated to reducing deaths, injuries, and property damage from motor vehicle crashes.

Although they both focus on improving automotive safety, they have different roles and functions. While NHTSA is responsible for establishing and enforcing safety standards, IIHS is focused on research, testing, and advocacy related to vehicle safety.

NHTSA safety ratings and crash tests

The NHTSA uses the 5-Star Safety Ratings system to provide consumers with information about the crash protection and rollover safety of new vehicles.

The Overall Vehicle Score (the number of stars from 1 to 5) considers the chances of getting hurt in certain accidents:

• 5 stars: Overall injury risk for this vehicle is much less than average.
• 4 stars: Overall injury risk for this vehicle is less than average to average.
• 3 stars: Overall injury risk for this vehicle is average to greater than average.
• 2 stars: Overall injury risk for this vehicle is greater than average.
• 1 star: Overall injury risk for this vehicle is much greater than average.

To calculate the vehicle safety score, the agency conducts frontal, side, and rollover resistance tests, which account for the majority of crashes on America’s roads.

Frontal crash test

A front crash test simulates a head-on collision. It involves two vehicles of similar weight and two crash-test dummies – an average-size adult male in the driver’s seat and a small-size adult female in the front passenger’s seat, both wearing seatbelts.

During the test, a vehicle crashes into a fixed barrier at 35 mph. The test is performed to evaluate head, neck, chest, and femur (leg) injuries.

Side crash test

The side crash test consists of two scenarios:

• A side barrier crash test simulates a situation in which a car is hit by another vehicle on the driver’s side (e.g., failing to stop at a four-way intersection).
• A side pole crash test simulates what happens when a driver slides off the road and crashes into a static object.

During the side barrier crash test, a 3,015 lb moving barrier crashes at 38.5 mph into a standing vehicle that contains two dummies (both on the driver’s side) secured with a seatbelt. The test evaluates head, chest, abdomen, and pelvis injuries.

Meanwhile, during the side pole crash test, a vehicle with a small-size adult female in the driver’s seat is pulled sideways at 20 mph and a 75-degree angle into a 9.5-inch diameter pole, hitting the car at the driver’s side. The test results evaluate injuries to the head, chest, lower spine, abdomen, and pelvis.

Rollover resistance test

Vehicle rollover resistance testing is based on an at-rest laboratory measurement known as the Static Stability Factor (SSF). It determines the susceptibility to rolling over during the high-speed maneuver after the driver loses control of the vehicle.

IIHS safety ratings and crash tests

IIHS evaluates two aspects of safety: crashworthiness and crash avoidance mitigation. Overall results are represented using a color code and four letters: G (Good), A (Acceptable), M (Marginal), and P (Poor).

Crashworthiness

Currently, IIHS maintains ratings in 3 crashworthiness evaluations:

• Moderate overlap front, where 40% of the total width of the vehicle traveling at 40 mph strikes the barrier on the driver’s side.
• Small overlap front that evaluates how the impact affects car occupants on the driver and passenger’s sides.
• Side tests that help evaluate how well vehicles cope with more severe side crashes

Since IIHS used to rate vehicles for roof strength and head restraints (both discontinued in 2022), you can still find these ratings when checking some older models on the IIHS website.

Crash avoidance and mitigation

As for crash avoidance and mitigation, IIHS performs tests in several other areas:

• Headlight evaluation. IIHS measures the reach of a vehicle’s headlights as the car travels straight and on curves.
• Front crash prevention. IIHS evaluates how well car safety technologies help to avoid hitting the target or lessen the severity of the impact.
• Seat belt reminder. IIHS tests various aspects of seat belt reminders, such as reminder timing, audible signal (sound level, pitch, duration), and visual indicator location. To receive a good rating, vehicles must meet all the requirements for both the front and second-row reminders.
• LATCH evaluation that involves Lower Anchors and Tethers for Children system check.

Differences between IIHS and NHTSA testing protocols

The key differences between NHTSA and IIHS overall ratings are their testing focus and the type of tests they perform.

NHTSA primarily conducts crash tests to assess vehicle safety performance according to federal safety standards. The organization focuses on evaluating how vehicles perform in standardized crash scenarios and ensures that they meet minimum safety requirements set by federal regulations.

IIHS, on the other hand, conducts a wide range of specialized IIHS crash tests and evaluations to assess vehicle safety performance in various real-world scenarios. The organization aims to identify areas where vehicles can improve safety beyond meeting minimum regulatory requirements.

Euro NCAP safety ratings and crash tests

Euro NCAP, or the European New Car Assessment Programme, is responsible for determining car safety ratings in Europe. Like its American counterparts, Euro NCAP performs crash tests and provides information regarding the safety of passenger vehicles.

Euro NCAP ratings use a five-star system (0 to 5), which provides insights into the safety performance of a car:

• 5-star safety: Overall excellent performance in crash protection and well equipped with comprehensive and robust crash avoidance technology.
• 4-star safety: Overall good performance in crash protection and all round; additional crash avoidance technology may be present.
• 3-star safety: At least average occupant protection but not always equipped with the latest crash avoidance features.
• 2-star safety: Nominal crash protection but lacking crash avoidance technology.
• 1-star safety: Marginal crash protection and little in the way of crash avoidance technology.
• 0-star safety: Meeting type-approval standards so can legally be sold but lacking critical modern safety technology.

Euro NCAP calculates the overall safety score by assessing 3 areas: Adult Occupant Protection, Child Occupant Protection, Vulnerable Road Users, and Safety Assist.

Adult Occupant Protection

The Adult Occupant Protection score significantly affects the overall car safety rating. It’s based on results from frontal, lateral, and whiplash tests, which assess how well a vehicle protects the driver and passengers, as well as the car’s ability to enable quick and safe rescue and extrication.

Child Occupant Protection

Euro NCAP evaluates child occupant protection for different age groups using specialized test dummies representing infants and children. These dummies are positioned in appropriate child restraint systems (CRS) corresponding to their age and size, such as rear-facing infant seats, forward-facing child seats, and booster seats.

The organization then conducts various crash tests, including frontal, side, and whiplash tests, as well as evaluations of CRS installation and compatibility.

Vulnerable Road Users

Besides assessing how well vehicles protect their occupants, Euro NCAP tests how they can affect vulnerable road users (VRU), such as pedestrians and cyclists.

Test scenarios include impacts with the front of the vehicle, such as the hood, windshield, and A-pillars, which are common areas of contact in pedestrian accidents.

Evaluation criteria consider factors such as the design of the front end of the vehicle, the presence of energy-absorbing structures, and the likelihood of head and leg injuries to VRU.

Safety Assist

Safety assist features are technologies designed to prevent or mitigate collisions and enhance overall vehicle safety. These systems use sensors, cameras, and radars to monitor the vehicle’s surroundings, detect potential hazards, and assist the driver.

When evaluating these features, Euro NCAP tests system functionality and performance during normal driving and in typical accident situations.

ANCAP safety ratings and crash tests

The Australasian New Car Assessment Program’s ratings (ANCAP) are largely aligned with the organization’s European counterpart, Euro NCAP. Therefore, the overall score is also determined from crash tests and safety assessments of on-board safety features.

In some cases, ANCAP may adapt certain aspects to better suit the Australian and New Zealand markets.

What other factors to consider alongside safety ratings?

While car safety ratings are essential when buying a car in the UK, you should also consider other factors to ensure the vehicle meets safety standards:

• Safety recalls and defects. Manufacturers issue recalls to remove all kinds of defects, including faulty airbags, sensors, and other advanced safety technology. Since manufacturers mainly send recall notices only once (to the current owner), you may not even know that a car you own or are about to buy is dangerous to drive.
• Differences between organizations. If you plan to buy or import a used car from Japan, Australia, or the United States, look up other safety organizations (e.g., NHTSA vs. ANCAP) that would help understand the differences in car safety ratings.