AAA Says Not All Automatic Braking Systems Are Designed to Prevent Car Crashes by Kirsten Korosec @FortuneMagazine August 24, 2016, 5:02 PM EST E-mail Tweet Facebook Linkedin Share icons Automatic car emergency brakes aren’t necessarily designed to prevent crashes, according to a study by the American Automobile Association. Some of the systems are merely intended to reduce the severity of accidents, an important detail that few drivers are aware of, the auto association said in a study published on Wednesday. The findings show a wide gap in performance for the emerging technology, which automatically applies the brakes in dangerous situations when drivers fails to do so. They also highlight the public’s deep misunderstanding about the limitations of the safety feature, which is expected to be a standard feature in virtually all cars sold in the U.S. by 2022. In the study, the AAA and Automobile Club of Southern California’s Automotive Research Center tested five 2016 model-year vehicles equipped with automatic emergency brakes including a Volvo XC 90, Subaru Legacy, Lincoln MKX, Honda Civic, and Volkswagen Passat. The AAA also surveyed 1,000 adult U.S. drivers to gauge consumer buying habits and trust of automatic emergency brakes. Get Data Sheet, Fortune’s technology newsletter. The study found that systems designed to prevent crashes reduced vehicle speeds once they were activated by nearly twice that of those designed to lessen crash severity. And yet, more than two-thirds of U.S. drivers familiar with the technology believe that automatic emergency brakes are designed to avoid crashes without driver intervention, said John Nielsen, AAA’s managing director of automotive engineering and repair. This lack of understanding could lead consumers to place too much confidence in their automated technology, and as a result, take greater risks while driving. In tests in which the vehicle traveled at under 30 miles per hour, systems designed to prevent crashes successfully avoided collisions in 60% of the time. Meanwhile, automatic emergency brakes designed to only reduce crash severity were able to completely avoid crashes in only 33% of test scenarios, according to AAA. Self-driving cars are blowing up the industry: Automatic emergency braking systems are offered as standard equipment on just 10% of new vehicles. As part of optional packages, the technology is available in just over one half of all new cars. About 9% of drivers said their cars were equipped with automatic emergency brakes, according to the survey. In the next several years, automatic emergency brakes are expected to become increasingly common. Toyota, for instance, has aggressively pushed automatic emergency braking, and says that 25 of 30 Toyota and Lexus models will have the technology as a standard feature by the end of 2017. That puts Toyota five years ahead of an agreed industry-wide deadline to make automatic braking a standard feature on all new cars by 2022. Twenty automakers, representing 99% of the U.S. auto market, have agreed to the 2022 benchmark, which was announced in March by the National Highway Traffic Safety Administration and the Insurance Institute for Highway Safety.