Safest and deadliest cars

BUYER’S GUIDE: Understanding Crash Test Ratings

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Safest and deadliest cars

One of the biggest considerations when buying a vehicle is its safety. No one wants to drive an unsafe car, especially when there are kids along for the ride. There’s a wealth of information available about a car’s safety, but it can be confusing. Here’s your guide to understanding crash test ratings.

Where to Start

Crash testing is so complex that there are multiple versions of these tests performed to determine if a new vehicle is safe. Every automaker conducts their own tests during the development process, but it’s the independent crash tests that carry the most weight.

The two big sources for crash test data are the Insurance Institute for Highway Safety (IIHS) and the National Highway Transportation Safety Administration (NHTSA). Each conducts tests and awards ratings based on how cars perform in different categories.

Unfortunately, not every vehicle made is tested. Crash testing is an expensive process, so you’re more likely to find results for cars that have higher sales volumes or have recently undergone a significant redesign. This doesn’t mean untested cars aren’t safe, but it does mean you’ll have to rely solely on the automaker’s data without independent verification of those results.

Insurance Institute for Highway Safety Tests

The IIHS conducts five crash test and awards rating of Good, Acceptable, Marginal, and Poor. Front crash prevention technologies are also evaluated and rated as Basic, Advanced, or Superior. Lastly, they consider headlights and child seat anchors (LATCH).

Any vehicle that receives Good ratings in all five crash tests is named a Top Safety Pick. That rating bumps to a Top Safety Pick+ through either Advanced or Superior front crash prevention technology ratings.

Moderate Overlap Front

This is the first of two frontal crash tests conducted by the IIHS. Frontal crashes are the most likely to result in fatalities so they receive extra attention. This test crashes a car into a 2-foot-tall barrier at 40mph with 40 percent of the car’s front end hitting that barrier. It’s designed to mimic a typical head-on crash between two vehicles of the same size.

Small Overlap Front

This new test started back in 2012 and is designed to mimic a crash with an object like a telephone pole or tree. It involves hitting a 5-foot tall barrier at 40mph with only 25 percent of the car’s front end hitting the barrier.

The smaller overlap means the force of the crash is concentrated toward the edges of a car, which aren’t as well protected as the front of a car. These types of crashes often cause serious leg and foot injuries and is why the IIHS started testing this type of collision.

Crash Test

Side Impact

This test involves sending a 3,300-pound barrier at the driver’s side of the vehicle at 31 mph. It’s designed to mimic an SUV hitting a car. This is an extreme test and one that would likely result in injuries in the real world but is survivable in a well-designed vehicle.

Roof Strength

A car’s roof strength is used to evaluate how well occupants will fare in a rollover accident. In this test, a metal plate is slowly pushed against one side of the roof until the roof is crushed by five inches. The amount of force applied to create this damage determines the vehicle’s rating in this category. The more force required inflicting the damage, the better.

Head Restraints and Seats

That head restraint isn’t there just for you to lean back and relax. It serves a purpose during an accident and can prevent whiplash during rear-end collisions. The IIHS evaluates head restraints by putting a test dummy in the seats and then moving the car on a sled that replicates a rear impact. This test uses both geometry and dynamic ratings to determine if a head restraint is effective.

First, it looks at how well-placed the head restraint is in relation to the occupant. It needs to be the right height and the right distance from the body in order to properly protect during a collision. Next, they conduct the crash test and measure the time it takes for the head restraint to connect with the occupant and the force of that connection. The combination of geometric and dynamic ratings determines the overall rating.

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Forward Crash Prevention

The advent of new crash prevention technologies led to the addition of this category in 2013. Testing here involves evaluating how well cars equipped with automatic emergency braking perform during a crash. Since the idea is to see how well a car does at preventing a crash, no actual collision occurs during testing. Instead, they use an inflatable target as a stand-in for a real car and put a real human behind the wheel.

The human engineer at the wheel drives towards the target at both 12mph and 25mph while sensors monitor how much the crash prevention systems slow the vehicle down before impact. If an impact is unavoidable, those sensors help determine how much the force of the impact was reduced. Since not all cars come with this technology, ratings can’t be done on every vehicle.

Prius V headlight

Headlight Evaluation

Headlights perform a vital role in preventing accidents. Engineers evaluate how well the beams travel straight ahead, through gradual curves, and through sharp curves. They look at both high beams and low beams with more weight assigned to low beams since they’re more often in use.

Lower Anchors and Tethers for Children (LATCH) Evaluation

Keeping children safe in the car is a major concern for parents. The IIHS looks at several factors when evaluating a car’s LATCH system for securing car seats.

The depth of lower anchors is measured to make sure they’re easy to locate. The clearance angle to access those anchors is also checked for ease of use. Even the force required to secure a car seat to the lower anchors is factored into the evaluation.

Tether anchors are checked to be sure they are optimally located and their proximity to other hardware is considered. There should be no risk of confusing a tether anchor with other hardware and accidentally securing a car seat incorrectly.

National Highway Transportation Safety Administration (NHTSA) TestsĀ 

NHTSA conducts three crash tests and assigns ratings from one to five stars. They also include information about crash avoidance technologies, but those technologies aren’t evaluated by the organization. Instead, they simply note whether or not key features are available.

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Frontal Crash

This test crashes vehicles into a barrier at 35mph. It’s similar to the IIHS Moderate Overlap Front crash test in that it mimics a typical head-on collision. An overall rating is assigned for the test, but there is also a more in-depth breakdown. A rating is separately assigned to the driver and passenger for a more detailed evaluation.


Side Crash

Side crash testing rating involves two separate tests. The first sends a 3,015-pound barrier into the side of a vehicle at 38.5mph similar to the Side Impact test conducted by the IIHS. They evaluate both the driver and passenger and assign an overall side barrier rating.

The second test involves angling the car at 75 degrees and impacting the driver’s side with a pole. This test assigns just one overall rating based on the driver. The results of both the Side Barrier and Side Pole crash test are then combined for the overall Side Crash rating.


This rollover test is very different from the one conducted by the IIHS. Rather than evaluating how strong the roof is to determine how protected you are during a rollover event, this test evaluates the risk of a rollover occurring in the first place. Test results show either a Tip or No Tip rating as well as a percentage risk of rollover occurring.

No car is perfect and there is always a risk of injury during an accident, but understanding how your car performs in crash testing will help you make an informed decision when it comes time to buy.

Looking for a new or used car? Check out BestRide’s listing search here.