This OPP photo is an example of an impact to a guardrail terminal where substantial energy was dissipated in a controlled manner.

There are not very many success stories being observed when it comes to vehicle impacts with guardrail terminals. Yesterday the Ontario Provincial Police uploaded a photo on their twitter account showing a potentially successful impact. The problem is, the driver still sustained serious injuries.

What is visible in the OPP photo is that the barrier bar has been split into individual sections and these sections have deformed into individual, curled ribbons. This is the type of deformation that causes the kinetic energy of an impacting vehicle to be dissipated in a controlled manner. Although there is damage to the front end of the vehicle that damage is moderate as exemplified by the lack of crush to the hood, no significant deformation around the left front wheel well, and the A-pillars are in their pre-crash state. So both the exterior of the vehicle and the barrier would appear to have done their job in working together to dissipate energy in a controlled manner. Such a combined dissipation means that the vehicle decelerates over a longer time and distance and therefore there is greater opportunity for the safety systems in the vehicle interior to perform in further reducing the severity of the forces exerted on the driver’s body.

So there is a little bit of mystery as to why the 81-year-old female driver of this vehicle sustained serious injury. It is not unusual to note that as persons age they are more frail and are prong to higher severities of injury than a younger person. But even so the severity of the forces that should have been exerted in this crash would be quite low provided that the interactions with the seat-belt and air bag systems were as expected.

This is another example where further probing is needed to determine what the specific injuries were and if they are the type that can be deemed acceptable. As an example, rib fractures might take place which are adjacent to each other and, because there is more than one fracture it ups the severity level of injury according to scales such as the Abbreviated Injury Scale (AIS). Yet if the driver had weak bones due to arthritis those injuries might be deemed understandable if they are not comminuted or displaced.

It is explanations such as these that can inform the public of the status of the safety systems around them and whether they are performing properly.