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Considered opinion sought on a matter of basic physics (collision of car and truck)

In this blog post I'm only discussing TECHNICAL issues, not anything else.


Let's assume my car was hit on its left side by the tray of a truck turning left at the left green signal (my car had a red signal at that time). Situation is depicted below:

(click each of the images for larger image).

The figure above shows very roughly how the 20 metre truck-trailer hit my car. Basically there was a massive angular rotation and application of force which can't be depicted in a simple diagram.


Assume that the truck company admits that "that there is a high probability that our client's trailer did in fact make contact with your vehicle and the damages sustained to your vehicle support this". However, the insurance agent denies that my car was stationery when the truck made contact with it. Instead it is alleged that my car was moving and wrongly overtaking the truck.


Please look at the actual damage and lete me know what you think (using basic physics). It is possible for such a damage to be caused by a MOVING car that is overtaking a truck trailer?


Here are three pictures of the damage caused:

Above: The arrows indicate the zone of damage, with the central portion (doors) being the most damaged. The left side rear view mirror was pushed FORWARD. Note also that the rips in the doors have been pulled FORWARD by the truck trailer.

Above: Front door on passenger side was pulled OUT and FORWARD by the truck's trailer.

Above: Back door pulled OUT and FORWARD by nearly 2 inches.


The figure below (roughly drawn by me) illustrates the physics of the accident.

The diagram on the left (above) indicates that damage caused is CONSISTENT with a moving truck and stationary car. There is extensive lengthwise damage and the doors have been pulled outward.

The diagram on the right (above) shows that if my car was moving (at a speed much faster than the truck), and bumped into it while overtaking it, then my car would have had two different kinds of damage:

a) NOT extensive length-wise damage but in a particular spot where there would be a huge dent; and

b) the doors  would have been pushed INWARD AND BACKWARD – not pulled outward and forward.

What's your considered opinion about the nature of the accident?

Sanjeev Sabhlok

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4 thoughts on “Considered opinion sought on a matter of basic physics (collision of car and truck)
  1. Rajat

    Hi Sanjeev,
    Here, it appears to me that that you were either stationery or moving at a slow speed (crawl) when the truck hit you. It is very hard to imagine how you could have been moving faster than the truck.

  2. Sanjeev Sabhlok

    Thanks, Rajat. I also spoke with an accident expert today. The Road Accident expert, after examining all details, photos, etc., has confirmed my personal analysis that the damage was caused to my stationary car.

    The expert has advised that there are three possible scenarios in which the accident could have occurred:

    i) stationary car hit by moving truck.
    ii) slow moving car attempting to overtake fast moving truck.
    iii) car reversing into truck.
    The third possibility (iii) does not exist on a busy street. 
    The second possibility (ii) does not exist since a slow moving vehicle can’t overtake a fast moving vehicle. Second, the truck started off at zero speed, and although it accelerated a bit, it was not going at any great speed. To try to overtake a slow moving truck by an even slower car is an impossibility. There is no scenario under which that could occur. 
    This leave only the first possibility (stationary car).
    So now I have two opinions (apart from mine) which confirm the absurdity of the counter-argument from the insurance company. They are trying to avoid paying up but the evidence is stacked against them (there is a HUGE amount of other corroborative evidence which I’m not discusing here).
  3. sukarna

    Respected Sanjeevji,

    I analyze the chance of option-ii is also very very less, If your car had been in motion in the direction of the truck (before bending of truck), then the 2nd tear off the next door would have not been possible. Your car would have naturally moved aside away from its original position due to the momentum received from the tray of the truck.

    So only possibility is the option-I


  4. Sanjeev Sabhlok

    Thanks, Sukarna This further bolsters the – to me obvious because it is true – case. The problem is with insurance company investigators who obfuscate and try to avoid liability.



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