By on March 27, 2012

I’m pretty good at taking tests. The problem is, with some tests that you take, success is not attained by giving the logically correct answer but rather by regurgitating the answer the test giver wants. I forget that sometimes. When the Michigan Secretary of State’s office told me that I needed to take a written test to continue to have the privilege of driving, on one question I forgot the proper test taking strategy was to determine what some bureaucrat in Lansing wanted me to think. Instead I just read the question, parsed its logic, and gave the same answer that I’ve given my now-adult children concerning the same driving situation. Wait. That’s a fib. I didn’t just read the question, parse etc. The question and possible answers intrigued me enough that I jotted them down on an envelope I had with me. They were unclear enough that I wanted to run them by the other TTAC writers and the Best and Brightest to get your opinions. Here’s the question:

Q. If you cannot stop before hitting another vehicle it’s usually best to:

A. Gradually slow down and hit the other vehicle.

B. Try to steer around the vehicle and avoid braking hard.

C. Release the accelerator and apply the brakes as hard as you can.

According to the bureaucrats in Lansing, the correct answer is B, try to steer around the vehicle and avoid braking hard. However, the question is about an unavoidable collision, you can’t really steer around a vehicle that you are indeed going to hit, can you? Now if I think about it, I can understand why trying to steer around a collision might mitigate that collision by avoiding head-on impact but that really doesn’t answer the actual question that was asked. I’ve been taught that, yes, under almost all circumstances you do want to maintain control and never, ever, lock up the brakes (well, with modern ABS that’s hard to do, so let’s say “stand on the brakes”), except for when you’re certain that you are going to hit another car or some other large object. When you absolutely can’t avoid a collision, I’ve been taught that you should do what you can to scrub off as much speed as possible before impact and that the best way to do that is to apply the brakes as hard as you can. That would make C the correct answer. Yes, you may lose control as the brakes lock up and the tires start to skid, but that’s the maximum coefficient of friction that you can create at that moment. It may not be a very controlled stop, but skidding to a stop can slow you down in a hurry. If you ice skate, think hockey stops. Locking them up is what you can do that will retard your speed quickest, it’s also just about the only thing you can do, or that’s what I’ve been taught. So what do you say the appropriate response is in the event of an unavoidable collision, try to continue to steer around the collision and avoid hard braking, or stand on the brakes and reduce impact speed as much as possible?

Ronnie Schreiber edits Cars In Depth, a realistic perspective on cars & car culture and the original 3D car site. If you found this post worthwhile, you can dig deeper at Cars In Depth. If the 3D thing freaks you out, don’t worry, all the photo and video players in use at the site have mono options. Thanks for reading – RJS

 

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91 Comments on “Ask the Best and Brightest: What Do You Do If You Cannot Avoid an Accident?...”


  • avatar
    Lokki

    When a crash is inevitable, I first roll down the driver’s window, and then throw the bottle as far from the car as possible.

  • avatar
    mitchw

    The logical answer to the question is B. The set up was that you could not stop; it did not say the collision was unavoidable. Therefore, avoid hitting the other car by altering your path, and don’t brake hard enough to lose control of the car.

    • 0 avatar
      aristurtle

      Yup. There’s plenty of times when I haven’t had the space to stop but have had the space to swerve, and of course when you’re swerving you generally don’t want to use the brakes at the same time. Maybe you should have run this one past Baruth or somebody before turning it into another RonnieRant about “the government”?

      If you never practice a swerve to avoid a collision this may not work; I’m glad the MSF class teaches this. If a standard driving test was half as thorough as the MSF Basic Rider Course there’d probably be fewer “accidents”.

      • 0 avatar
        Tosh

        “RonnieRant” indeed…..

      • 0 avatar

        “Maybe you should have run this one past Baruth or somebody before turning it into another RonnieRant about “the government”?”

        I thought that the question was ambiguous enough to ask it of a wider audience. To wit, from the original post:

        “They were unclear enough that I wanted to run them by the other TTAC writers and the Best and Brightest to get your opinions.”

    • 0 avatar
      Philosophil

      That’s how I read it as well. Nowhere in the question does it say that an accident is unavoidable. It says that you cannot stop in time to avoid hitting another vehicle (with the emphasis on ‘stop’). Therefore the correct course of action is to override your urge to stop and to try swerving around the vehicle instead.

    • 0 avatar
      thesal

      Agree, B is logical.

      The question and possible responses have still been worded in a very awkward/misleading way. A test is only as good as it’s questions. If a capable driver who would do the right things in the situation but has been misled by the unclear wording of the question illustrates a failure of the test, not the driver.

      PS. When we get Santorum in the hotseat, there will be an option D. – Jesus take the wheel!

    • 0 avatar
      srogers

      I failed the reading comprehension test. I first chose C because I assumed that they meant that an impact was unavoidable. Now that I’ve been educated by wiser posters, I’d choose the correct answer, B – unless there’s a chance of hitting another vehicle/person/expensive obect by doing so.

      So really, the question is ambiguous and poorly written.

      • 0 avatar
        aristurtle

        The question tests whether or not the reader assumes that a collision is unavoidable merely because the obstacle is within your car’s stopping distance. Seeing the words “cannot stop before hitting” and mentally substituting “unavoidable collision” is exactly what the question is testing for.

        So I think it worked.

        Moreover, I’m going to take it farther and say that usually, finding yourself without room to stop before you hit something probably means you were driving too fast for conditions, tailgating, not paying close enough attention to your surroundings, etc. I know there are exceptions to this; I said “usually”. My own collisions certainly have all fallen into one or more of those categories, anyway.

      • 0 avatar
        docrock

        And this type of mentality – “the question is ambiguous and poorly written” is ever present, ie the Federal Tax code.

      • 0 avatar
        JustinM

        Except, docrock, that this question is neither poorly written nor ambiguous. Assuming anything other than exactly what is written is the fault of the reader, not the writer. It is clear from a straight reading of the question what was intended: “If you cannot stop before hitting another vehicle” does not indicate “If you cannot avoid hitting another vehicle”.

    • 0 avatar
      Dynamic88

      +1 The accident is not unavoidable. You read that into the question. It was not vague.

  • avatar
    stuntmonkey

    I was taught “B” as well… but emergency maneuvers is something you need to practice to overcome the instinct to hammer the brakes. Circle-of-traction stuff… if you’re braking the tires have less friction for swerving. I was only taught to hammer (well, threshold brake, this was before ABS) the brakes if there was no room to swerve to the left or right. (Just a note, I think most stats indicate that drivers tend to swerve away from danger, putting their passengers at increased risk of injury or dying)

    Then again, most collisions seem like they are avoidable before you get into them.

  • avatar
    kitzler

    I probably would have picked B if that had been a DMV driver’s test. However, I know of many instances where you need to stop and cannot do it in enough distance, like rounding a curve and seeing a rock on the asphalt, or barreling down an unfamiliar country road and suddenly seeing a stop sign. In that case, my innate reaction is to hit the brakes as hard as I can, no time to think really, just a gut reaction.

    However, if the reason to stop was not a rock or stop sign, but a vehicle or a pedestrian, my driver’s instinct would be to turn the steering wheel to the right and hit the ditch or curb, or even the car next to me. Hitting a stopped vehicle is worse than the guy who is moving alongside you at almost the same speed,

  • avatar
    Robert.Walter

    D. Check the clean underwear supply in the glove-box.

  • avatar
    RayH

    The answer is B or C depending on the situation, IMHO.

    In my last instance of an unavoidable accident, a large herd of deer was in the entire roadway over a “blind” hill with no shoulder to speak of. I probably should have just slammed on the brakes, but instead I jerked the steering wheel to the left, pulled up the emergency brake and slid sideways, I believe only hitting one. I was in a car, I wouldn’t do that in a truck, and I had no passengers. I don’t recall how fast I was going, but that was my instinct at the time, and it only cost me a dented rear fender and the deer I hit ran off, presumably okay.

    • 0 avatar
      gslippy

      I once encountered a rolled-over car whose driver swerved to avoid deer (at night, of course). Fortunately, she wasn’t hurt, and I think her car was salvageable, but it could have been much worse.

      Animals are expendable.

      • 0 avatar
        ciddyguy

        My Mom hit a dear once, it darted out in the road in front of us at dusk, fortunately, she was only going at best, maybe 40mph, if that in a small town and this was the main drag with woods off to one side. The dear only glanced off the car and bounded off to the woods. it came at us from our right and continued on past us to our left after being hit, only a small dent in the hood was the damage to the car and it’s really a smallish dimple at that and that was her ’04 Dodge Stratus.

    • 0 avatar
      krhodes1

      If you are going to hit something, you WANT to hit it head on. That is how the car is best able to protect you – the most crumple space, the most effective seatbelts and airbags. And distribute the impact over as much surface of the front of the car as possible – offset collisions are bad business.

      Sliding sideways into something is not a good option at all.

      Of course, for a really, really high-speed impact, you want to be rolling and tumbling instead of the dead stop in three feet.

      For the example given, B is certainly the correct answer.

      • 0 avatar
        WheelMcCoy

        @krhodes1 “If you are going to hit something, you WANT to hit it head on.”

        That’s what the cop unintentionally but negligently did here in this disturbing ttac story:

        http://www.thetruthaboutcars.com/2012/03/avoidable-contact-do-cops-really-have-the-need-for-speed/

        Cop survived. The 2 teens in the Mazda didn’t.

      • 0 avatar
        krhodes1

        @WheelMcCoy

        A textbook example of why you do NOT want to be hit or hit sideways. Had that been a head-on, there is a sporting chance the kids would have survived.

        Of course, had the kid had the situational awareness to not turn left in front of an on-coming car, they would still be alive too – he was dead wrong on that one unfortunately. Not that this excuses the cop in any possible way for doubling the speed limit.

      • 0 avatar
        Buckhead55

        My own recent experience confirms this. Four months ago, coming over a hill on a two-lane highway, I was struck head-on by a car passing in a no-passing zone. I had no time to react. Both cars were doing at least 60 mph. Drivers and passengers in both cars survived with no life-threartening injuries.

    • 0 avatar
      frenchy

      I was told that you should always hit the animal in the road instead of trying to avoid it. The reason being if you roll your car and don’t hit anything else it’s your fault. If you hit the deer it’s an act of god.

    • 0 avatar
      rpn453

      It’s hard to believe that pulling the e-brake while in motion would be instinctive to anyone. I used to play with that a lot as a kid too, but only to induce instability! Maybe it was the best option though.

      I usually slam on the brakes and hit the air horns simultaneously when I see wildlife on the road. I’ve only had one really close call though, and I didn’t even have time for that. The deer jumped from a ditch and I swerved before I could even think about it, barely clipping him. I can still picture him taking up pretty much the entire front view through the windshield as he leaped across. I didn’t see him until that moment. It was an empty twinned highway and I even swerved in the right direction, so it was absolutely the perfect thing to do, but I’m not sure how much of that was luck because there was no time for thought. I hope I wouldn’t instinctively do that if I had other traffic around me, especially if it were a non-divided highway.

  • avatar
    gslippy

    First, I agree that the question implies an unavoidable impact. So in practice, I would do “C”, but for the exam I suppose B is the right choice.

    I had an experience just like this (my fault… speeding in city traffic), and to swerve around the car in front of me would have meant involving other vehicles, and a possible rollover. A straight-on rear-end impact was all that occurred (pre-airbag era).

    However, my father’s solemn advice was to never, ever hit a pedestrian. In the case of a pedestrian, do whatever you must to avoid hitting them.

  • avatar
    George B

    If the crash is unavoidable, you need to convert as much kinetic energy to heat before the remainder is dissipated in the other object, the crumple zones of your car, and your body. I’d choose C and let the ABS do its job. This assumes normal dry pavement traction but insufficient distance to avoid the crash.

    • 0 avatar
      gachapingymkhana

      I’m not sure I’d agree with the author that skidding produces the most friction. Adding to George’s point on heat conversion, I’d assume that brake pads generate less waste heat when locked up than when unlocked, and in that sense locked breaks would involve a more efficient (in this case less desirable) transfer of energy. Admittedly, locking the breaks allows energy to escape as heat through the screeching tires… but then molten rubber can slide across pavement in an annoyingly smooth fashion.

      Another way to look at it is to consider that it takes a lot of effort to start dragging a heavy object, but that once it’s moving it becomes easier to keep it sliding along. Applied to a car this would mean you’d want to avoid the sliding state, instead keeping it just on the verge of sliding, where more energy is expended with less to show for it. But with ABS it’s not something you have to think about.

  • avatar
    patman

    What I’ve learned from watching professional stunt drivers and crash testers crash into things on science-y-ish TV programs is that right before impact you should take your hands off the wheel and hold them out, as if you were being robbed stick-em-up style, to avoid injury from from the airbag.

    Steer around. I see people do that all the time – they head for the shoulder when they realize they’re about to rearend the line of traffic. And with almost everything having ABS these days, it actually works! My brain’s meter is still calibrated for crappy tires and brakes that lock up at the drop of a hat ’cause there have been countless times I thought an inattentive driver was going to plow somebody in the next lane but they end up stopping well short.

  • avatar
    Verbal

    D. Start crying.

  • avatar
    mcarr

    Q. If you cannot stop before hitting another vehicle it’s usually best to:

    It does not say a crash is unavoidable, it says you cannot stop. This wording makes B the correct answer. If it had been worded to say that a crash is unavoidable, then C is the correct answer.

    Move along, nothing to see here…

  • avatar
    Pch101

    “If you cannot stop before hitting another vehicle…”

    is not the same question as

    “What Do You Do If You Cannot Avoid an Accident?”

    The question isn’t presuming that the crash is unavoidable. The question is presuming that relying on the brakes alone will not enough.

  • avatar
    Bancho

    Eject! Eject! Eject!

  • avatar
    Detroit-X

    D. Push Toonces paws off the steering wheel before the airbag goes off.

  • avatar
    Educator(of teachers)Dan

    My father used to tell me (BTW I was driving an $800 car in 1993 when given this advice.) “Hit something cheap.”

  • avatar
    burgersandbeer

    Did you pass the test?

    • 0 avatar

      96%. There were a couple of other ambiguously worded questions that I split. Two wrong out of fifty isn’t terrible. I wonder what a passing score is.

      • 0 avatar

        HOLY CRAP! That’s a really draconian test if you didn’t pass with a 96%! Or did you mean “I wonder what the lowest possible passing score is…?”

      • 0 avatar

        Sorry for not being clearer. Yes, I passed and yes, that’s what I meant about the lowest passing score.

      • 0 avatar
        Steve65

        Except that there’s nothing ambiguous about that question. PEBCAK.

      • 0 avatar
        Firestorm 500

        Based on the drivers around me, the passing threshold must be pretty low.

      • 0 avatar
        doctor olds

        @Ronnie Schreiber- Apparently, you do not have to pass the test at all, at least in Michigan! The last time I renewed my license at a Michigan Secretary of State office, the clerk told me to complete the test, then, “go to the counter and get your license.” I asked, “What if I don’t pass the test?” Her response, “Oh, you don’t have to pass the written test to get your license. We will just tell you which questions you got wrong.”

      • 0 avatar
        dtremit

        The last time I took the test — which was in ’96 — the passing score was pretty low. Maybe 70%? But I think there were only about 20 questions.

        I remember similarly arguing the answer to one of the questions — the only one I got wrong. If I recall, it was “When you wish to pass another car on a two-lane highway, what is the first step you should take?” The answer they were looking for was “Check the yellow line to see if passing is permitted.” I answered “Check for oncoming traffic,” with the logic that you’d want to check for an obvious impediment before taking your eyes off of traffic to check the line…

        Amazingly, the MI rules of the road booklet is still called What Every Driver Must Know.

  • avatar

    I’m missing option “D. Pray/hope for the best” in case of oncoming vehicles suddenly on your lane.

  • avatar
    GS650G

    http://rmirror.net/r/videos/comments/q5hu9/car_accident_nsfl/

    Any suggestions on this one?

    • 0 avatar
      Bancho

      Wow, that SUV seemed to disintegrate.

      My only suggestion would be for emergency crews to bring a mop.

    • 0 avatar

      A good argument for divided highways. The 401 in western Ontario used to be almost as bad as that – lots of head ons. That video is chilling to watch because you know it wasn’t survivable. I once got detoured off of I-94 because a truck driver fell asleep and ended up on the wrong side of the interstate. It took a while to find out how many victims were in what was left of the car it hit.

    • 0 avatar
      GS650G

      It appears he was accelerating to pass the panel truck and the left wheel lost traction on the snow line. He tried to save it but overcompensated. Bouncing off the panel truck was bad enough and he had the misfortune to cross in front of the rig.
      As they say, it was his time. Anyone that thinks a Silverado or Expedition is a “tank” needs to rethink that belief.

  • avatar
    DC Bruce

    I think the right answer is B, too. I’ve had two collisions/almost collisions in my 45+ year driving career. In the first, when I was in college driving on I-95 thru Connecticut at night in the rain, there was one of those all-too-common instances where road construction eliminated a lane (in this case, the center lane; I was in the left lane). For unknown reasons, some car ahead of me braked pretty hard and by the time it was my turn to stop, I knew I wasn’t going to be able to do it — with the crummy bias ply tires of the time. So, I bailed out to the left on to the grass in the median, staying off the brake. I accomplished this maneuver withe complete success, keeping the car pointed in the right direction, and just lifted with a plan of letting the car coast to a stop (on the wet grass, I knew using the brakes would be risky). Unfortunately, for reasons known only to them, the road engineers placed several curbings across the grass perpendicular to the direction of travel. Given the poor visibility I didn’t see them until the last minute and braking was out of the question. So, I blew the front tires on the first curbing as the car became momentarily airborne. The impact lifted the V-8 engine enough that the distributor, which was on top of the engine against the firewall, cracked, leaving me with no power. Nevertheless, I rolled to a complete stop without hitting anyone. There was substantial damage to the car’s undercarriage, but none to the body.

  • avatar
    lw

    I have to disagree with everyone. The answer depends on two variables…

    1) is this your fault or the fault of the other guy?
    2) what is the size of his vehicle vs. yours?

    For example, if it’s his fault and he’s driving a something much smaller than you, then mash the accelerator and learn him some F=M*A!

    • 0 avatar
      rpn453

      Liability is actually a big factor. My first instinct is to scrub speed by braking hard and staying in my lane to avoid creating any further damage for which I would be at fault. Only if I were completely aware of my surroundings and absolutely certain that there would be no collision if I swerved would I consider getting off the brake and steering out of my lane.

      I’ve simply stayed in my lane and braked both times I’ve been hit, and in both situations there was no doubt that the other guy was at fault. To me, that’s the most important thing. I trust the car to best protect me with the wheels pointed straight and the front end taking the impact straight-on.

  • avatar
    afflo

    Motorcycling has made me a better driver in this regard. I’m far more proactive and alert for escapes from danger since becoming a rider. If you suddenly find yourself with no way to avoid a collision, chances are you’ve done it wrong. And, in a modern car (how many cars DON’T have ABS and traction control these days?), you have far less to worry about as far as maintaining control if you swerve.

    I had an Element when I went through the MSF Basic RiderCourse. I decided to take that “swerving practice” they hammer to my 4-wheel conveyance. The squirrely handling of a topheavy SUV with a short wheelbase quickly got me back into standard cars!

    • 0 avatar
      Mark_MB750M

      Me too. Even in the car I use the SIPDE technique from MSF. MC riding makes me more alert as a driver.

      I would have answered B, too.

    • 0 avatar
      GS650G

      I’ve been on 2 wheels my entire life, a bicycle is a good way to see the country and the most vulnerable vehicle there is.

      The best advice for motorcycle riding is to assume everyone is trying to get you and it’s up to you to avoid them.

  • avatar
    DenverMike

    Steer a split second before standing on the (non ABS) brakes, just enough put it into a slow rotation. Your hands are already on the wheel and a split second ahead braking anyway. Just before the impact zone, straighten the wheel to 12:00 o’clock and let off the brakes a bit and it’ll shoot you into the next lane or whatever open area with only the speed you haven’t scrubbed off. Of course ABS takes less talent but longer to scrub off speed.

  • avatar
    Firestorm 500

    An earlier post said that locking up the brakes and skidding the tires gave the best stopping ability.

    Wrong.

    Your best stopping ability comes just prior to lockup. Since this is difficult for most people to judge, especially in a panic stop situation, ABS brakes were invented.

    In an ABS car, stomp and hold the brakes as hard as you can. The ABS system will cycle the brakes many times faster than you can to stop the car in the shortest distance possible.

  • avatar
    ciddyguy

    When I first read this a couple of hours ago (had to fix dinner in time to see a special in high def on PBS), I instinctively picked what would have been B, swerve around the car in front if possible.

    That was what i was taught and have had to do when I felt I could not stop fast enough, especially one time in Dad’s 83 citation with crappy brakes. Traffic in front of me on I-5 slowed down suddenly and I hit the brake pedal, only to meet excessive resistance and the car was slow to slow down, so I swerved to my right, thankfully I was in the right lane so could pull off the freeway if necessary, but was able to stop the POS car none the less.

    I’ve seen others do that very same thing when necessary, including one older Toyota 4×4 pickup when we all had to slow down suddenly and he swerved onto the shoulder and when he stopped, he was almost to my door to my right in the curb – and that was in the Mt Baker Tunnel westbound one day coming home from work a couple of years or so ago.

  • avatar
    x-hdtestrider

    One of my jobs working for Harley-Davidson was training new riders. Working the night shift in the middle of the desert, their were nights when several things would run into your path. Swerving to avoid was always the wrong answer. When a new guy would do that one of two things would happen. First they would ride into soft dirt and flip the motorcycle,or go off the side of a cliff, or they would drive into on coming traffic.
    It was my job to train new riders on riding safty, and break them of this bad habit.
    Rabbits and coyotes were a nightly test of man-hood.
    The wild donkeys and deer, were big enought you could see them most of the time, and slow down.
    Of couse not every night.

  • avatar
    MrBostn

    There are no “accidents” Crashes are caused by lapses in judgement, reckless behavior and bad decisions.

  • avatar
    Mark MacInnis

    I just think, “What would Baruth do?” Then, saw the wheel to the left aiming at the space the object I am about to hit is now, knowing that it won’t be there when I get there…

  • avatar
    Felix Hoenikker

    If the impact is truly unavoidable, I would yell out at the top of my voice “I’m going to move you” and brace for impact.
    It didn[t work too well when the Titantic hit the iceberg, but it’s worth a try.

    • 0 avatar
      Madroc

      The physics are all different, but the Titanic reference is oddly apt and maybe even applicable here.

      When the Titanic’s lookout spotted the iceberg, the deck officer commanded full reverse on the engines, and right (?) full rudder. But the cavitation caused by the reversed screws disturbed the water flow around the rudder and made it less effective, increasing the ship’s turning radius, so it turned just enough to sideswipe the berg and tear open a huge gash on the hull. Had they commanded full reverse on the engines and kept the rudder amidships, the ship would have hit the berg head-on and limped into Newfoundland under its own power. Had the crew maintained speed and commanded full-right rudder, it would have cleared the iceberg entirely.

      And the moral here, I think, is to steer around the obstacle if you can, but hit it with the part of the car designed to hit things if you can’t. Having once spun a car into the oncoming lane in a successful-but-foolhardy (luckily there was no traffic) effort to miss a deer, I’m now inclined toward the latter, especially if it’s likely to be the other driver’s fault and I’m not *absolutely sure* that my evasive action won’t cause another accident anyway.

  • avatar
    Austinpowerless

    Just a quick note for anyone who buys Mr. Schreiber’s contention that locked up wheels provide the shortest stopping distance for a car. Absent a very loose surface (like loose gravel or powdery snow)a car whose wheels are locked up will stop in a LONGER distance than a wheel whose brakes are applied just short of the force needed to lock them up. I thought this was an enthusiast’s site, so I thought this would be common knowledge, but apparently not–it’s called threshold braking.

    Locking up your brakes= longer braking distance, period. No engineers on the site, either, apparently.

    • 0 avatar

      You’re absolutely correct about threshold braking and stopping distances, however locked tires on pavement has a very high coefficient of friction and you will scrub off a lot of speed. You may not be doing it in a controlled manner but you will slow down. The point is not to stop quickly, because you’re not going to avoid the accident. The point is to reduce impact speed.

      It’s sort of a moot point since all new cars and a significant part of the overall motor vehicle fleet now have ABS, so panic stops are likely to be very close to threshold braking.

      • 0 avatar
        Austinpowerless

        Sorry, but you’re simply contradicting yourself. You wrote:
        “The point is not to stop quickly, because you’re not going to avoid the accident. The point is to reduce impact speed.”
        Unfortunately, that’s not just a false dilemma, it’s a contradiction in terms. To “stop quickly” and “reduce impact speed” are, by definition, the SAME GOAL, i.e., reduce the rate the car is travelling in the shortest time possible, or, in other words, achieve maximum deceleration. Yes, locked tires on pavement scrub off a lot of speed, but not as much as threshold braking does.
        If you want to reduce impact speed, do not lock your brakes.

        Of course, the reality is that an ABS system will come closer to true threshold braking than 99.9% of drivers 99.9% of the time, so, as you poiont out, this is academic.
        However, the notion that standing on the brakes and sliding luridly is a good crash mitigation strategy (where you have plenty of time to modulate the brakes) is nonsense.
        Locked braking is a mistake, always, if the goal is to slow down as quickly as possible. That you also lose steering ability when fully locked up is just an added penalty.

        Edited: Incidentally, if you know that locked up wheels don’t produce the shortest stopping distance, why did you write, “Locking them up is what you can do that will retard your speed quickest”? That’s just false, and, apparently, you know it.
        If you meant that in the real world the minor penalty of increased impact speed due to locking the brakes is the best that can be expected of a typical driver in an emergency, and that having the same driver attempt (and probably fail) to retain steering control and achieve absolute max deceleration through threshold braking is not realistic, then we’re in agreement. (Moreover, abs means stomping IS the best strategy, for cars so equipped.)
        Unfortunately, you didn’t write that. You wrote that locked up brakes scrub off the most speed (in fact, you wrote it twice). That’s just wrong.

    • 0 avatar
      krhodes1

      While I completely agree that threshold braking will result in the best possible stopping distance, the reality is that very few members of the driving public have the Baruthian skills to do it correctly. Especially in an emergency situation. Better to nail the brakes as hard as possible, and do as much deceleration as possible, before the wheels lock up. Most cars don’t have such amazing brakes that the wheels will lock until the speed has been reduced considerably.

      And never forget, the primary purpose of ABS is NOT to shorten stopping distances! It is to maintain steering control, even at the expense of longer stopping distances. This is particularly true of older cars with 3-channel ABS systems, and/or relatively slow cycle times of the ABS solenoids. The latest and greatest systems actually do have the hardware and software to exceed the threshold braking of an expert driver, but you won’t find such systems on cheap cars even now.

      • 0 avatar
        afflo

        “Better to nail the brakes as hard as possible, and do as much deceleration as possible, before the wheels lock up. Most cars don’t have such amazing brakes that the wheels will lock until the speed has been reduced considerably”

        In an age where even cheap cars have antilock brakes, electronic brakeforce distribution, brake assist, and stability control, and a true emergency situation will come up with such suddenness that you basically jump to muscle memory* and do what you’ve trained yourself to do, the best bet seems to be to stab the middle pedal and try to steer around.

        *This is, afterall, what everyone does, usually followed with rationalization of the actions afterwards, i.e. the classic motorcyclist claim that “I just had to lay her down to stop” when they really panicked, locked the brakes, and lowsided). I mentioned the MSF focus on practicing safety maneuvers – I learned to drive, like all but the youngest drivers, in cars without ABS. I realized the definite need for this when I got caught driving inattentively and had to stop quickly, and jumped to the learned “brake pumping” action. When the chip are down, you’ll do what you do, not what you rationally assess to be the best course of action. Practice those moves!

  • avatar
    deliverator

    To me the two scariest situations is driving are these:
    1. In city driving, say in a four-lane road, low-speed, two lanes in each direction. With intersections every block, either with lights or not. You’re in the right hand land and a line of cars is stopped in the left hand lane. Are they stopped for a pedestrian crossing or because someone is turning? Double jeopardy – someone not looking properly decides to dart into your lane because he doesn’t want to wait behind the turner. Basically you have no choice but to slow down.

    2. On the highway/freeway, if you are changing lanes, either to the left or right, at normal speed, and someone in the lane next to the lane you are changing into decides he wants to be in the same spot. Since I have my mirrors set correctly and do a shoulder check to the immediate left or right of me before changing lanes, in the very short time interval between checking and moving into that lane, the other person decides to do the same. Only if one or both of you notice this is happening will the situation work out.

    What do you guys think?

    • 0 avatar
      aristurtle

      As a motorcyclist I have a somewhat lower tolerance for collisions than most drivers.

      1) Slow down as you pass the line of cars; stay aware of the cars around you and keep to the right side of the lane. Not only could one of them jump out of line at you, but the car in the left lane of the opposing side of traffic might not see you and use the opportunity to make a left turn across your right of way. (This is a disturbingly common cause of motorcycling accidents).

      2) When changing lanes, make sure you check the lane beyond it; if possible find a spot where it’s clear as well.

    • 0 avatar
      afflo

      1. Yeah. This especially gives me the willies on a motorcycle, compounded by the predilection of Texans to suddenly shift lanes without signals or head checks, and it seems most common among drivers of the largest vehicles (Suburbans and crew-cab pickups), who either can’t see or just don’t care. Drive friendly… right.

      2. Texas gives priority to the car coming into the lane from the left. I’m not sure about other states. It certainly raises the point that a shoulder check/mirror check should involve the next two lanes, not just the adjacent one.

      The one that gives me the willies is having someone slow WAY down, or just never speed up, when entering a freeway, either waiting for someone to wave them in, or worse, just entering the lane without checking on the assumption that drivers will move to the passing lane to accomodate them. The latter is not unusual on empty rural interstate highways, but in an urban/suburban setting, you better get up to speed and look for a hole!

  • avatar
    SimonAlberta

    OK, I am coming a bit late to this party but, for what is worth, here is my input;

    Sheldon Cooper in Big Bang Theory would have a field day with this one.

    The question is: “If you cannot stop before hitting another vehicle it’s usually best to:”

    MY question is: Usually best for WHOM or WHAT?

    Best for my own selfish preservation needs?

    Best for minimizing general carnage?

    Best for avoiding death or injury of other parties?

    Best for minimizing legal liabilities?

    etc. etc. etc.

    In short, the question is so utterly vague and every crash scenario so different (road conditions, speed, other traffic and a hundred other variables) that to get the “correct” answer you have to guess what the examiner WANTS you to answer.

    In no way does the knowledge of the “correct” answer to this question further the general safety of new road users.


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