A Crash Course On


A Crash Course On

Vehicle Safety Ratings

One of the most common questions members ask AAA is, "What is the safest car?" While there's no way to determine which vehicles provide the best protection in every possible crash, testing conducted by the National Highway Traffic Safety Administration and other groups provides a standard by which to compare different models.

Government crash testing

The National Highway Traffic Safety Administration, part of the U.S. Department of Transportation, is in charge of reporting on the crashworthiness of new vehicles. Each year, NHTSA tests new cars, trucks, and vans, focusing on those that have received major redesigns or new safety features.

NHTSA conducts four separate tests, measuring the impact forces inflicted on crash test dummies that simulate different-sized drivers and passengers. Vehicles are rated using the 5-Star Safety Ratings system, with five stars indicating the highest safety rating and one star the lowest. Models receive a rating for each test, as well as an overall crash survivability score.

Mouse over a star to learn more about it.


This test remotely drives a test car into a wall, simulating a head-on collision at 35 mph. Frontal crashes are heavily influenced by vehicle size and weight, so ratings can only be compared with similar models.


This test simulates a T-bone impact on the driver’s side from another car in an intersection. A 3,015-pound barrier is crashed into the stationary test car at 38.5 mph.


This test simulates a driver losing control of their vehicle and sliding into a telephone pole on the driver's side at 20 mph.


This test simulates a car driving on a highway and coming upon a sharp curve, identifying how well the car resists rolling over during severe turns.

Independent crash testing

The insurance industry funds the Insurance Institute for Highway Safety, which performs its own independent crash testing. IIHS tests are generally considered to be more severe than NHTSA’s, and they cover some types of crashes that NHTSA does not.

IIHS rates vehicles as good, acceptable, marginal, or poor based on each of five crash tests. It also assigns a basic, advanced, or superior rating to vehicles’ front crash prevention technology systems. Cars that perform well across all tests are designated Top Safety Picks for their model year.

  • Good

  • Acceptable

  • Marginal

  • Poor

Mouse over a rating to learn more about it.

Video courtesy of IIHS.org


To simulate a frontal offset crash between two vehicles going just under 40 mph, a test car with a dummy in the driver’s seat hits a 2-foot-tall deformable aluminum barrier at 40 mph. Forty percent of the width of the vehicle strikes the barrier on the driver’s side.

Video courtesy of IIHS.org


In this test, a car with a dummy in the driver's seat impacts a 5-foot-tall rigid barrier at 40 mph on the driver's side. Only a quarter of the vehicle's width strikes the barrier.

Video courtesy of IIHS.org


A 3,300-pound barrier designed to mimic an SUV hits the driver’s side of the test vehicle at 31 mph. Two dummies ride in the test car to simulate a driver and a passenger.

Video courtesy of IIHS.org


A metal plate applies steady pressure to one side of the test car's roof. For a rating of "good," the roof must withstand a force at least four times the vehicle's weight before being crushed by 5 inches.

Video courtesy of IIHS.org


Restraint designs are first evaluated on having proper geometry. Those designs that rate "acceptable" or better (nearly all do) are then tested in a simulated rear impact with a dummy to gauge real-world forces to the head and neck.

Crash avoidance technology

A quickly emerging field in auto technology is designing vehicles that help drivers avoid crashes altogether. It’s likely that these innovations will culminate in self-driving cars that eliminate human error, but until then, a number of systems can help their human occupants drive more safely.


Radar or cameras sense when cars are beside and behind your vehicle, then alert you to prevent an unsafe lane change or other maneuver.

  • Systems usually have warning lights on the rear-view mirrors.
  • If you switch your signal on when a vehicle is detected in your blind spot, the system provides an additional alert.
  • The system may also have a cross-traffic alert that warns of oncoming vehicles when you back out of a parking spot.


Cameras or other sensors read road markings to help you stay in your lane.

  • If you begin to drift out of your lane, the system alerts you with lights, sounds, vibration, or a combination.
  • Advanced lane-keeping systems can also use the steering wheel or brakes to nudge your car back into its lane.
  • These systems are deactivated when the turn signal is on.


Cameras monitor your head and face for telltale signs of drowsiness.

  • If the car senses you're falling asleep, it sounds an alarm, and may suggest stopping to get some sleep or a cup of coffee.
  • Some cars generate "driver profiles," checking your driving against those patterns to see if you might be drifting off.


Sensors detect vehicles ahead of yours, automatically adjusting speed to keep a safe distance.

  • Most systems allow drivers to decide how much of a gap they want to maintain.
  • If the car you’re following moves out of your lane, cruise control accelerates to the top cruising speed you've set.


Like adaptive cruise control, this system monitors forward traffic, looking for potential hazards such as stopped cars.

  • Warning systems alert you that a crash is likely if you don’t begin braking or maneuvering.
  • Mitigation systems warn you as well, but also take steps to lessen the damage in a crash, such as automatically braking and tightening seatbelts.

Which car is safest?

While it's impossible to come up with a consensus pick for the single safest possible car, savvy shoppers can compare their options across categories to arrive at the safest vehicle that fits their needs, looking at models that:


Have high scores or ratings from NHTSA and IIHS testing


Are equipped with advanced collision avoidance technology


Are larger or heavier, which correlates with occupant survivability

Speedometer icon

Still meet your performance and fuel economy needs

A convenient way to compare safety and fuel economy at the same time is the AAA Green Car Guide, which annually reviews and rates zero-emission, alternative-fuel, and other eco-friendly vehicles. One of the evaluation areas, crashworthiness, takes vehicle weight and number of air bags into account. Each vehicle also has its NHTSA crash rating published, if available.

Information taken from "How to Select the Safest Car," the Automobile Club of Southern California's Automotive Research Center, June 26, 2015.