By on October 21, 2011

Usually it’s the Germans who we find continually pushing the crash-test envelope, but this time around the UK’s Fifth Gear TV Show that decided to crash a car at 120 MPH. Sure, the Germans already proved how much of a difference can be made by crashing at 50 MPH instead of the traditional 40 MPH, just as the Chinese can make any of their cars appear safe by testing at 35 MPH rather than 40 MPH. But 120 MPH? It’s never been done before…

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38 Comments on “And Now: The 120 MPH Crash Test...”


  • avatar
    sean362880

    “…a head-on collision on a 55-MPH country highway could easily deliver this level of impact”

    No it can’t. A car traveling at 60 mph hitting another car going at 60 mph in the opposite direction decellerates from 60 to 0, assuming a totally inelastic collision.

    The car in this video decellerated from 120 mph to 0. MUCH different.

    • 0 avatar
      kilgoretrout

      Obviously they don’t watch enough “Mythbusters.”

    • 0 avatar
      InstantKarma

      Sean is quite correct. It’s about kinetic energy. 2 Cars at 60 mph have twice as much energy spread over twice as many cars as 1 car going 60 mph. 120 mph to 0 is ugly.

      • 0 avatar

        Such pedantry! Can we agree that this more closely reflects what might happen in a 60 MPH vs. 60 MPH head-on collision than anything we ever see from NHTSA, IIHS, Euro NCAP etc, which don’t test impacts greater than 40 MPH into a stationary object?

      • 0 avatar
        Russycle

        Sorry Ed, no we can’t. 60 MPH into a brick wall might be a somewhat reasonable simulation of two cars crashing at 60, but 120 is off the charts. Mythbusters laid this out pretty nicely.

      • 0 avatar

        Dear god do I need a vacation…

      • 0 avatar
        Sinistermisterman

        I’m with Mythbusters on this one. 60mph car vs 60mph car = 60mph crash. 120mph car vs Brick wall = 120mph crash.

      • 0 avatar
        Ingvar

        Does it really matter? There are plenty of stupid and careless people out there killing themselves in 120 mph. I especially remember that girl taking her fathers Porsche out for a joyride and slamming it right into a concrete pillar foundation.¨Was it a toll both of some kind? The point is, forces like that are in action, the video shows what happens when a car is caught between a rock and a hard place.

      • 0 avatar
        saab_lurker

        Twice the speed means 4x the kinetic energy.

      • 0 avatar
        Pch101

        Does it really matter?

        It does. Head-on collisions between two vehicles, with each vehicle traveling 120 mph (192 km/h), almost never happen. This sort of crash would be such a statistical outlier among crashes that the odds of it occurring are next to impossible.

        This is one reason why that opposite directions of traffic are separated on superhighways. When the risk of head-on collisions is nominal, it is possible to drive safely at higher rates of speed.

    • 0 avatar
      philadlj

      The occupants of two cars hitting each other head on at 60 mph and those in one car hitting a wall at 120 will be equally dead, most likely.

      • 0 avatar
        krhodes1

        Not true at all. Hitting a wall at 120mph is indeed most likely to kill you – see Dale Earnhardt. Hitting a wall at 60mph (which is equivalent to a 60mph head-on, sort of) is actually pretty survivable, assuming you are riding in a good-sized modern car with your seat belt on. You will not be out of the hospital for a long time, but given decent EMS and Trauma center care you will probably live. Lady luck plays a significant role, of course.

        But hitting a wall is always, always, always the worst case scenario. The way you want to crash from high speed is to be firmly buckled in and roll the thing over and over. Spread the energy over as much distance as possible.

        In the late 80′s a friend in an ’81 Subaru (an utter death trap by modern standards) went off the side of I-95 at ~70mph. He hit a drainage culvert and went END-OVER-END 9 or 10 times. Clear impact dents in the ground from the front and rear of the very much shortened Subaru. Walked away from it with a broken finger and whole lot of cust and bruises. The perfect high speed crash. Dissipated all that energy over about 1/8 mile, rather than the 4-5′ that hitting a bridge abutment would entail.

      • 0 avatar
        rpn453

        I was hit in an (approximately) 60 mph vs. 60 mph head-on with a slightly larger car. My ’87 Grand Am wasn’t nearly as safe as that Focus, and I (barely) survived! The other guy had a compound fracture of his femur. Mine was a compound tib/fib with the bottom part of my leg folded under the seat and my leg pinned by what used to be the floorboards. After comparing crash videos of similar cars to those of modern cars, I don’t think I’d have even been injured in my current Mazda3.

      • 0 avatar
        CompWizrd

        my sister-in-law did the end over end thing.. She was driving an ’88 Jeep, and was doing 70+ mph and did end-over-end 7 or 8 times. What saved her was when the jeep landed on her head, the seat broke. From there the front and back formed a nice triangle, with what was left of the bent roll bars holding up. After that accident, we stripped the jeep. I removed the _passenger_ seatbelt(no one was in that seat) from the vehicle by yanking on it. the rusted out anchor points ripped out. This Jeep had just passed a safety a few weeks before. Suspect it never actually got seen by a mechanic. She was in the hospital overnight for the head hit, and has a nice scar on the hand… otherwise walked away from it.

  • avatar
    shntnu

    Actually, it is a highly implausible scenario; it would require two cars to be travelling at 120 MPH when colliding, not 55 or 60.

  • avatar

    From the above “a head-on collision on a 55-MPH country highway could easily deliver this level of impact.”

    No, it can’t.

    A car hitting the proverbial immovable object at 120 mph is not at all like two cars hitting each other head-on at any speed other than 120mph.

    No need to re-invent the bent wheel, see: http://www.physicsforums.com/showthread.php?t=456239&page=2

  • avatar
    alex159569

    There is a big difference between hitting an immovable object at 120mph and going from 120 to zero in a few milliseconds as stated in the video and two cars sharing the impact and also having the ability to bounce off each other and continue moving which takes a huge edge off the impact. Sensationalism more than anything.

    • 0 avatar
      rpn453

      Not that big. With two cars at 120 mph, there’s twice as much energy to be dissipated by twice as much car structure.

      In my crash situation that I described above, our cars remained almost right beside each other after the impact.

  • avatar
    Steven Lang

    The Ford Focus hatachback had the worst side impact scores in North America a few years ago and was among the worst on front impacts.

    They should have used an Ariel Atom.

  • avatar
    grzydj

    I just got an email from Sir Issac Newton about this.

    RE: FWD 120 mph crash OMG U MUST SEE THIS LOL!

    Third law.

    That is all,

    S|rn3wt

  • avatar
    saab_lurker

    Heaven forbid TTAC give props to the Swedes. It’s always the Germans.

  • avatar
    OldandSlow

    There is a moral here and a very clear one. Stay out of cars that impact an immovable object at 120 mph.

    • 0 avatar
      DenverMike

      I don’t think immovable objects get the respect they’re due. A friend hit a larger oak tree at 40 MPH and died at the scene. The Silverado he was driving was completely fubar’d and he didn’t even hit it dead on. Actually he glanced off of it from the passenger side.

  • avatar
    FreedMike

    FUBAR – Webster’s definition

  • avatar
    mitchw

    I regularly drive on a four lane highway with no barrier between directions. Cars are closing on each other at 100+mph. There used to be a double yellow line until the roadway was recently repaved. Driving that road at night, trust me, is so sickening that no one uses the left lane right now. It really hurts in your guts to drive mere feet from a net oncoming 100 mph car. This is in NY on 22 near the Mt Kisco reservoir.

  • avatar
    "scarey"

    The narrator stated (at 1:02 into the video) that the crash was equivalent to two cars going 120 mph colliding head on. I am pretty sure that THIS is not right.

    • 0 avatar
      graham

      While the narrator’s comment is not correct for the reasons already stated above, it IS a better representation of two cars colliding at 120mph then it is of two cars colliding at 60mph.

      The most realistic test would be to use two CARS traveling at 120mph to create the crash test, or to use a fix barrier that closely reflects the dynamic properties of a modern car. And to better replicate real-word accidents, ideally it would be a frontal offset crash to simulate an oncoming car partially swerving into “your” lane. IIHS already performs those tests, but only at 40mph.

  • avatar
    Dimwit

    That was amazing. Does anyone know what the NCAP score was for that year/model?

    • 0 avatar
      geggamoya

      Four stars, http://euroncap.com/tests/ford_focus_1999/34.aspx

    • 0 avatar
      redmondjp

      There is no amount of stars in the crash rating or enough airbags that would keep you alive in a crash like that!

      The sudden deceleration alone will kill you. Your aorta simply pops open (as it did on Princess Diana) and your blood pressure goes from 120 to zero about as fast as the car does. And your brain colliding with the inside of your skull makes sure that the job is finished! Car race crashes have proven this, with the likes of Dale Earnhardt and (just recently) Dan Wheldon, RIP.

  • avatar
    M.S. Smith

    I’m always amazed at how many people talk about how they “safely” hit 120 in their Honda Civic on car forums. It’s everywhere except may the Toyota Corolla fansite.

    A stock vehicle simply is not meant to deal with this sort of speed. It doesn’t matter when it was built.

    In fact, this rather reminds me of a kid I knew high school. He had a V8 Firebird, of the early 90s vintage I think, and went plowing down a road at 100+. He caught some air over a bump, lost control, and completely annihilated the car and himself. I remember going to the crash scene the next day, and there were still bits of the interior and broken CDs that had spilled across the grass as the car’s frame came apart.

    He did survive, for which he was incredibly lucky, but spent many months in the hospital.

  • avatar
    chuckrs

    If you want to figure this out for yourself, get a good introductory physics or engineering text. Halliday and Resnick or Beer and Johnston both will work but there are plenty of others too. Look at the conservation of energy equation, but for figuring out the deceleration the impulse and momentum equation will tell you the average deceleration if you know duration of the crash. The trick for manufacturers is to get that actual deceleration curve as close to the flat line average as possible for as many accident scenarios as possible. All while making a car that people want to buy.

    Here’s what the texts will tell you.

    1) car into barrier at 60mph dissipates 1/4 the energy of car into barrier at 120mph – so does your body if you are in that car
    2) roughly the same energy dissipation would occur in the highly unlikely case of two cars head on at either 60/60mph or 120/120mph.
    3) no points for the deformation of the opposing car – symmetry considerations mean it doesn’t matter
    4) the small rebound that might occur means the total deceleration is greater than if the collision were perfectly inelastic – not by enough to matter in the slightest at 120mph – cars don’t ricochet around like pool balls
    5) no such thing as a perfectly balanced symmetric collision – a barrier won’t give you what any actual collision will, but each actual collision will be slightly different anyway – that’s why you try and set a reasonable, easy to replicate standard, like a barrier……

    • 0 avatar
      redav

      It’s even simpler that that. The point of collision between two identical cars is a plane of symmetry. As such, no momentum can ‘flow’ over/through/across it. If there is no flow across this plane, then everything on the other side can be removed and simulated with a fixed barrier (immovable concrete wall).

      This is a basic technique for setting up free-body diagrams.

  • avatar
    Robert Schwartz

    http://www.wreckedexotics.com

    Very Instructive.


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