By on August 24, 2016

car crash (Daniel X. O'Neil/Flickr)

Automatic emergency braking is finding its way into more and more cars (and automakers have a pact to make it standard equipment by 2022), but most drivers don’t know the technology’s limitations.

AEB systems slow or stop a vehicle in an emergency, preventing or mitigating a crash, but an American Automobile Association study shows that 71 percent of U.S. drivers familiar with the technology believe AEB will prevent all crashes.

AAA partnered with the Automobile Club of Southern California’s Automotive Research Center to test five 2016 models equipped with AEB. The tests showed the systems worked more or less as planned. During 70 trials, vehicles with AEB designed to prevent crashes slowed by twice the amount as those designed to simply slow the vehicle before impact.

Vehicles designed to prevent crashes shed, on average, 79 percent of their speed before impact. Those designed to mitigate the crash slowed by 40 percent. In tests conducted at speeds of 30 miles per hour or less, crash-avoiding AEB systems prevented 60 percent of the planned collisions

Still, there were some surprises in store for researchers. Under 30 mph, the systems designed to only lessen the impact actually avoided a collision 33 percent of the time.

At higher speeds, the performance of both systems diminished. At 45 mph, the crash-avoidance systems slowed the test vehicle by 74 percent, on average, and prevented collisions 40 percent of the time. The lesser AEB system only reduced vehicle speeds by nine percent.

Obviously, any reduction in speed helps the vehicle’s occupants. A speed reduction from 30 to 20 mph cuts the energy of an impact by 50 percent.

Still, the majority of drivers believe that all AEB systems will prevent a crash, without the need to manually apply the brakes. There’s a risk that motorists in AEB-equipped vehicles will become overconfident in their vehicle’s abilities. Slowing to 36 mph before hitting another vehicle is a far different outcome that avoiding the other car completely.

“The reality is that today’s systems vary greatly in performance, and many are not designed to stop a moving car,” said John Nielsen, AAA’s managing director of Automotive Engineering and Repair, in a statement.

Currently, nine percent of Americans drive a vehicle equipped with AEB. By September, 2022, virtually every new light-duty truck and car will carry the technology as standard equipment.

[Image: Daniel X. O’Neil/Flickr]

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44 Comments on “Automatic Emergency Braking Won’t Always Stop a Crash, But Americans Think It Will...”


  • avatar
    SC5door

    So that’s why the 147 was held up…..a CAMERO driver!

  • avatar
    Ryoku75

    Looks like KITTs seen better days.

    • 0 avatar
      White Shadow

      Firebird….not Camaro. And I bet it the Camaro was selling better, they would bring back the Firebird. Oh wait, no more Pontiac. Scratch that. Lolol

      • 0 avatar
        sgeffe

        Too bad that branding restrictions prevent “one-off” names in a GM dealership! (Not that they make anything worthy of the “Oldsmobile Cutlass” name nowadays!)

  • avatar
    28-Cars-Later

    Micheal, we seem to be entering an intersection and the light is still… CRASH.

    • 0 avatar
      DukeGanote

      Given that the common causes of crashes are (1) opposing traffic, (2) crossing traffic, (3) sharp curves, and (4) roadside hazards… Only looks like a means to reduce front-to-back impacts. Useful at bogged intersections and freeways. Could reduce some crashes and some insurance costs, but not many deadly crashes. Call this KITT 0.15

  • avatar
    Fred

    So, if I step on the gas instead of the brake, will it prevent me from crashing into a store front?

  • avatar
    poltergeist

    You mean to tell me physics trumps marketing? Probably the same stupid 71 percent of people that bought into the story that ABS would save their ass when they follow too close….

  • avatar
    Pch101

    One of the basic problems with humans is their tendency to rely upon their experience, feelings and perceptions, even when those are often wrong, rather than using facts and data.

    Hence, the issue here. If the technology requires much human interaction and training in order for it to work properly, then people will invariably not understand it and they can be expected to misuse it. If their “gut feelings” tell them the wrong thing, then they’ll still be inclined to follow their gut. Since it isn’t possible to fix the humans, one must fix the product.

    • 0 avatar
      TrailerTrash

      “an American Automobile Association study shows that 71 percent of U.S. drivers familiar with the technology believe AEB will prevent all crashes.”

      “Still, the majority of drivers believe that all AEB systems will prevent a crash, without the need to manually apply the brakes.”

      So, wait…they began to not apply their brakes????

      Pch…we really can’t believe this study, can we?
      If these 71 percent dummies really believed this, then they would never use their brakes!
      So they MUST know they need to be in control and use their brakes…or they would never use them!

      And so, if you really believed you AEB would stop you, why are you interfering and applying your brakes!!!???

      Kinda reminds me of the question that was asked of a extremely religious fanatic once. Sorta went like this….If you were a true believer in the concept of heaven and spending eternity with your savior in bliss, why in hell are you taking medications and trying so hard to stay here!?

      The other part of this “study” is the unusual amount of times the freakish number 70 showed up.

      shows that 71 percent
      During 70 trials,
      79 percent of their speed
      slowed the test vehicle by 74 percent, on average,

      Yup…70 percent pretty freakishly starnge….

  • avatar
    Higheriq

    And here come the lawsuits from the idiots and ambulance chasers who believe “the manufacturer’s ads led me to believe the car would prevent me from rear-ending that school bus”.

    • 0 avatar
      SlowMyke

      Well there’s a few problems I see here that’ll lead to your conclusion: people don’t read manuals, sales people don’t teach about the product, and advertising is loosely based in reality at best.

      The manual thing is the owner’s problem, but the other 2 are the dealership and manufacturers problems. I’ve never seen a commercial for a car with some kind of brake assist that didn’t show a driver innocently distracted being saved by the car coming to a full stop from moderately hard braking. It’s a new technology and companies want to advertise it, but they’ve got to do it appropriately and also educate the customer. I’m not one to advocate many “save us from ourselves” rules, but if you know people don’t read manuals, and you are vague in commercials about what the limitations are, it’s only logical that people will not understand the product.

      • 0 avatar
        runs_on_h8raide

        “Well there’s a few problems I see here that’ll lead to your conclusion: people don’t read manuals, sales people don’t teach about the product, and advertising is loosely based in reality at best.”

        You had to just stop at people do not read, which is the vast problem, despite having the manual hand delivered to them. Every car I’ve ever purchased, and its quite a long list of cars, has said to read the manual for more in-depth about the car, and if you don’t the consumer is a fool, to be honest. There’s a reason why they give you the manual by hand during delivery. It is to read it, and it is also a requirement per CSI. So no…it’s not the salesperson’s fault. Part of the job is to show and demonstrate how the car works and what are the pros/cons of the systems vs. the competition while the consumer shops and then again at delivery for more in-depth should they purchase the vehicle. Do all do it, probably not, but a definite supermajority do because their CSI’s are tied into it, and if they don’t do the delivery right, their CSIs get crushed, and they don’t make bonus, which is tied into CSI at nearly every car dealer in America. So the vast majority of salespeople will show how these things work, and especially if the consumer demands more attention to it at delivery. So to say the salespeople do not teach, you are simply stating your opinion like its fact, which it is not, and not even close to how it works in the real world. When was the last time you bought a car? Surely, if it was very recently, you had to know this, or are you one of those people that scrounge every last cent below invoice and then fluff off the salesperson at delivery and say, just give me the keys I’ll figure it out later, and then blame them for not knowing how bluetooth pairs up with audio system?

        It is not the much maligned salesperson’s responsibility to read the manual to the consumer at bedtime for Mr. and Mrs. Jones. It all falls on the consumer. The manufacturer specifically gives separate manuals for collision avoidance systems. If the consumer chooses to ignore it after buying their car to reinforce what was taught, that is their problem, and their problem only. People need to take more responsibility for their own actions instead of passing it off when they falter.

        Quite frankly, especially here on TTAC, the consumer is the all-knowing god vs. the dealership and sales…so to blame anything on the dealer and salesperson, is actually, quite hypocritical. Which is it…consumer is the all-knowing one, and the salesperson a scumbag always and doesn’t care? The exact opposite? I’d say its a combo, with more consumers actually being the dumbasses they truly are…with a pumped up overinflated view of themselves. If you need proof, just go out on the highways of America and see how they drive, and it doesn’t matter if its a Mercedes or lowly base model Kia owner, most Americans drive like absolute dog crap, eschewing laws and all other semblances of common courtesy.

        • 0 avatar
          SlowMyke

          Like I said in my post, the buyer is at fault for not reading. But these are very complex products being sold, and new technology ought to be highlighted given the obvious misconceptions over what it actually does. And since we have a consumer-friendly legal system, it would be wise for the manufacturer/dealer to be proactive. I also find the commercials obnoxious and cloying in the way they present the brake assist features.

          As far as the rest of that rant, sure man. People suck at driving. It’s a product of crappy education, self-centered thinking and action, and lack of interest in being a good driver. All that has created the need for this nonsense technology to save us from ourselves.

          EDIT: Aside from all of our ranting about this, we apparently were all click-baited with this article anyway, as pointed out below…

        • 0 avatar
          sgeffe

          The only law many people follow, to my chagrin, are the numbers on a “Speed Limt” sign! And even then, the first number of the two is interpreted as one lower, extending the wagon-train of enraged drivers behind me!

  • avatar
    Jerome10

    71% believe it will prevent ALL crashes??!!

    Jeez. One of those stats that makes you shake your head.

    • 0 avatar
      CH1

      The AAA report doesn’t say what TTAC claims it does..

      The report says:

      “Drivers who currently own a vehicle equipped with automatic emergency braking system are more likely to trust it to work (71 percent) compared to drivers that have not experienced the technology (41 percent).”

      None of the above statements imply that people expect AEB to avoid all crashes. Only 9% of drivers own vehicles equipped with AEB. So the 71% of owners who trust the technology amounts to only about 6% of American drivers. The majority of drivers who own vehicles without AEB (91% of all vehicles) don’t trust the technology.

      Bottom line: Only about 43% of American drivers trust AEB technology and trust doesn’t mean they expect it to avoid all crashes.

      • 0 avatar
        Russycle

        Thank you. Steph, WTF?

      • 0 avatar
        285exp

        The report also says:

        “AAA found that two-thirds of Americans familiar with the technology believe that automatic emergency braking systems are designed to avoid crashes without driver intervention,” said John Nielsen, AAA’s managing director of Automotive Engineering and Repair.

        • 0 avatar
          CH1

          “The report also says:

          “AAA found that two-thirds of Americans familiar with the technology believe that automatic emergency braking systems are designed to avoid crashes without driver intervention,” said John Nielsen, AAA’s managing director of Automotive Engineering and Repair.”

          Yes, so …?

          Nearly all Americans believe modern medicine can cure diseases, which is quite different from saying nearly all Americans believe modern medicine can cure ALL diseases.

          The “two-thirds of Americans familiar with the techonology” are the 71% of drivers who own vehicles with AEB (9% of all vehicles) mentioned later in the report. 59% of owners of the remaining 91% of vehicles don’t trust AEB.

          Most people familiar with AEB (i.e., owners of vehicles with AEB) know the systems have limitations. They know the systems are not active at all speeds, lighting and weather conditions; and that crash avoidance depends, for example, on relative speed.

          Nearly all of us trust modern medicine, but we also know modern medicine cannot cure all illnesses.

          • 0 avatar
            TrailerTrash

            You are correct. In fact my system, one of the earlier, on the 09 MKS is constantly beeping and warning me when the system has become disabled, whatever the reason.It could be snow, rain or dirt…but I was given the warning.

            I love the system and the idea. I has saved me and is always warning me…even when I know its a bit early and needless. I prefer being warned, just in case.
            The system cannot judge real life, such as my judgment on the car in front about to turn and get out of my way. It cannot tell what was preventing the car ahead from moving has recently gone and the car ahead will soon leave my area.

            But the system is awfully nice to have as a background back up.

            IF I could make any suggestion to manufacturers, it would be to warn all drivers the auto cruise and lain adapter has been turned off in any really heavy traffic. Nobody should be relying on auto cruise when in heavier traffic. Just plain stupid.

            Put your foot on the pedal and get in complete control. I cannot fathom any Tesla driver trusting autopilot in traffic. Insane.

  • avatar
    APaGttH

    It was the valet. It is always the valet.

    www [dot] you tube [dot] com / watch?v=6N7iaaa5ko4

  • avatar
    chuckrs

    Reducing speed by 79% reduces the energy to shed (ie, that you are subjected to) during a collision by by over 95%. Even if you assume the duration of the collision is the same at full speed and at greatly reduced speed, the peak forces to which you will be subjected are reduced 79%. Reality will be somewhere between, but either way, it is a big advance for lower speed travel – suburban and urban. Our idiocrats will see this as permission to go faster still. Not surprising at higher speeds the observed benefits are reduced. For impending higher speed accidents where you don’t got no traction, it doesn’t matter how smart your car is about braking.

  • avatar
    energetik9

    One of the biggest concerns I have always had is that most Americans do not know the capabilities/limitations of the car they drive every day and certainly approaching limit. The fact that these numbers don’t understand what an automatic braking system does not surprise me in the slightest.

    Not advocating to dive into a stationary object to learn the system, but at least read about it.

    • 0 avatar
      dwford

      American drivers seem to fall into 2 camps:

      #1. The death grip on the steering wheel because the car will fly out of control any moment crowd
      #2. The laws of physics don’t apply to me crowd

      • 0 avatar
        sgeffe

        #1 is common!

        Woman last week doing 50 in a 65 — in an Accord V6! Yet I could see that she was practically breaking the rim! (Which is pretty thick!)

        What’s the point?!

  • avatar
    bunkie

    When I was taking Driver’s Ed, I happened to be taking Physics at the same time. Learning to drive cemented Newton’s Laws in my brain. Learning to fly has further reinforced them.

    Most people who crash (on the road or in the air), have some fundamental misunderstanding of how the physical world works. Traction, stall speed, momentum, minimum air speed, it’s always the same: they push beyond what is actually possible, preferring to trust their *feelings* rather than to respect the limits imposed by the natural world.

    I realize I’m echoing PCH’s comment, but my point is that training (such as pilot training) is often not enough. My instructors repeated the rules of thumb again and again. I take that to heart. A surprising number of pilots die each year because they can’t bring themselves to do the right thing when face with a physical impossibility.

    No matter how good the tech is, you will not stop in 50 feet from 60 mph. No matter how much you want to, an attempt to return to the runway without sufficient altitude after an engine failure on takeoff *will* result in a fatal stall-spin.

    Don’t get me wrong, the new safety features are really great. But they do little to allay the extreme stupidity or ignorance of some people when they are operating beyond the limits of possibility.

  • avatar
    thelastdriver

    When I had a stick Geo Prizm (this was recent) it was fun pissing off other drivers by idling along in first at a constant speed during a jam. Only time I’d ever have to clutch/brake was when some impatient fool jumped in front of me.

    Hate to sound like a conspiracy theorist but this is the beginning of the decline of humanity, folks. Machines are thinking for us so we’re not thinking!

  • avatar
    Lightspeed

    This explains why every winter I will be driving my 30-yr-old RWD car on the freeway and see the ditches littered with trucks and SUVs of which 90% are AWD/4X4/FWD.

  • avatar

    I drive a 2016 Accord with auto breaking, driving in NYC, the system will come on warning you to brake at least 5 times in an hour long drive in traffic, in the last 5 month or so that I have the car, the system actuated the brakes about 5 times, it makes me feel safe but at the same time I can’t really rely on the system alone to save me every time, same as with the adaptive cruise control, it’s really cool that the car accelerate and brake according to traffic but I always keep one foot very close to the brake pedal, I’m sure some people just rely on these systems to save them every time, not me.

    • 0 avatar
      APaGttH

      I know that Honda has had some quality issues in the last decade, but I wasn’t aware they were selling automobiles with a feature that includes automatically breaking.

      Can you pay more to get a reliable 2016 Honda Accord without the auto breaking feature?

    • 0 avatar
      raph

      I’d hazard a guess that the people who rely on AEB just don’t want to be bothered with driving like the guy who set out to prove that Tesla’s Autopilot was incorrectly named(However I will respect the fact that he martyred himself so that the rest of humanity can profit from his courageous actions!).

      My deceased 2015 Mustang GT had auto braking and adaptive cruise control which were pretty neat features but I never really became comfortable with both systems.

      • 0 avatar
        sgeffe

        Especially since, as I’ve stated, you have to adjust your perspective a bit by watching your six, lest you get rear-ended if the car nails the brakes more abruptly than you might.

  • avatar
    Blackcloud_9

    Probably most people believe it will work is because all of the advertising I have seen always show the vehicle stopping in time and avoiding the impending disaster.
    The only vehicle reviews I have seen that report on the AEB is on MotorWeek…Waiting for B&B to stop thinking of snarky John Davis comments…and they have reported that AEB doesn’t always work.

  • avatar
    Trucky McTruckface

    Breaking news: Human stupidity threatens ability to maintain oxygen inhalation.

    Film at 11.

  • avatar
    CoreyDL

    “Still, the majority of drivers believe that all AEB systems will prevent a crash, without the need to manually apply the brakes.”

    Yeah, people are stupid. And they rely on and trust technology too much – implicitly and instantaneously. They assume because they have a feature, their guard and common sense can be disabled.

    See: Tesla Autopilot
    See: GPS crashes
    See: AWD overconfidence
    See: ABS overconfidence
    See: Backup cameras

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