Recognizing Collision Facts From Patterns of Damage in Head-on Collisions

Knowing what a typical pattern of damage in a head-on collision should look like can be useful in understanding what happened seconds before an impact.

As I have measured damaged vehicles from hundreds of severe frontal impacts I have also created large scale diagrams and matched “points of mutual contact” that can be used to follow the progress of the motion between initial contact and separation of the vehicles. During these detailed studies I developed the understanding that there are typical and common patterns of crush and they are correlated to some pre-collision happenings. A knowledge of these facts can help investigators to understand what evidence is likely to exist and what needs to be documented before it is lost. But this knowledge can also be used by the general public to evaluate when something shown in photos of police and official news media is not exactly as it has been reported. These interpretations are not foolproof nor are the damage patterns absolutely distinct from one another. Generally these interpretations cannot stand alone unless there is some very specific and obvious evidence that indisputably leaves no other interpretations. While such singular, indisputable evidence is not common it is also not wise to ignore the obvious fact when it exists.

For the purposes of education I have selected a recent fatal head-on where the OPP have made the photograph of the two vehicles public. Before continuing on I want to acknowledge the obvious fact that this was a tragic event where someone has lost their life and there are family and persons who are greatly affected by this tragedy. On the other hand there are no convenient times or ways to discuss these important matters. Education is an important element in preventing future tragedies and in providing justice to those who may be wronged by a system of justice that sometimes acts like a bull in a china shop.

So below is the noted photo of the two vehicles at their final rest positions. Many pages of detailed comment can be made about this happening and this will  simply lose the readers’ attention so I will be brief.

I have often discussed previous incidents where the patterns of damage are unusual, at best, and may not reflect the description provided to the public. In proceeding to describe what the damage should look like it becomes difficult to provide that visual in words. So the above photo helps in that it shows the most common form of crush that occurs in a severe head-on collision.  It shows the fact that head-on collisions that occur on highways, at highway speeds, create offset contacts. What I mean is that the vehicles do not strike each other, license plate to license plate, but that the direct contact is offset. In a high percentage of impacts the offset of the direct damage is to the left. In other words there is direct contact to the driver’s side of the front end and there is no direct damage toward the passenger’s side of the front end. Next, both vehicles will exhibit very similar patterns of damage/crush. The maximum crush will be at the left corner of the both vehicles and there will be progressively less crush toward the right until the point where there is a major “deflection point” where the right corners of the vehicles exist and the crush suddenly becomes much less. The damage to the right of this deflection point is typically “induced damage” and is differentiated from the “direct damage” in many ways.

Next we will note that the right front corners of both vehicles will be pulled to the left. This happening is quite obvious in both vehicles shown in the above photo. This pattern of (rather) identical damage patterns has been previously described as “book ends” in that both vehicles look the same. This pattern of damage is most commonly associated with instances where one driver may be involved in a passing motion and is unable to return to his/her own vehicle in time and the opposing driver has not applied sufficient counter-steering to make a large difference. Thus both vehicles are coming toward each other at 180 degrees. The actual approach angle in the example shown above cannot be known because we cannot see the left sides of the vehicles and that is crucially important. So let’s leave this discussion as it is for now so as not to lose the readers’ attention.

Now, when we do not see this very common pattern of damage and someone talks about a passing motion with no driver reaction then our ears should begin to perk up and we should look a little closer. We do not conclude that there is something wrong in what we are told, but we simply pay more attention to what else might be involved. In reality this discussion becomes much more complicated but at least, for now, we have observed what is the most common and typical pattern of damage in a serious head-on collision.