The Canadian Broadcasting Corporation (CBC) has recently broadcast a documentary (The Fifth Estate) and published articles discussing its investigation into an alleged improper decision by Transport Canada to prevent school buses from being equipped with seat-belts. An article published on the CBC website on October 14, 2018 claimed that “thousands of injuries” and “numerous deaths” would have been prevented if school buses were “on school buses”.

While I respect the CBC’s many admirable documentaries that enlighten Canadians about important issues, this latest discussion has missed the mark and may be more misleading than it is helpful.

As an example, the CBC website article showed photographs submitted by Kirsten Hodgeson of a 2008 school bus collision near Rimbey, Alberta where the bus was rear-ended by a gravel truck resulting in the death of a 17-year-old passenger. Two photos of that rear-ended bus are shown below.

In this 2008 rear end impact it was claimed that the deceased passenger of the school bus would have been saved if she was not ejected from the bus and it was the ejection that was the cause of her death.

Keenen Clark, a student who survived this crash, claimed that it was his ejection from the bus that caused his major injuries.

Keenen Clark,  a student who survived the crash was quoted as saying “if seatbelts would have been on the bus, Jenny (Noble) probably would have stayed on the bus. Everything that happened to me happened after I fell out of the bus”. Referring to the crash the CBC seemed to agree, noting “..the need for seatbelts seems obvious”.

The need for seat-belts is a separate issue, but the discussion of this rear-ended school bus incident is misleading and harmful to the understanding of the important issues. The school bus was reportedly stopped in fog when it was struck by a gravel struck which glanced off the right side of the bus and came to a stop a short distance ahead. The impact was of a narrow offset such that one can see that the main structural components of the bus, such as its frame, were not deformed and were not involved in the dissipation of the truck’s kinetic energy. In short, the collision was not one where the bus sustained a large change-in-velocity. Change-in-velocity is what is used to determine the severity of an impact and its potential to cause injury. The primary issue in this crash was that the relatively soft structure of the bus was crushed resulting in substantial intrusion into the passenger compartment. This intrusion can be seen in the above photo where the seats of the bus have been deformed and displaced. The fact that some passengers were ejected from the bus was not the primary issue as their ejection from the stopped bus should have been at low speed and of minimal injury potential. For this collision the important factor that would lead to injury/death is the structural intrusion and not the change-in-velocity or the ejection. Seat-belts are often of minimal effectiveness when there is substantial structural intrusion into where the occupant is seated, as was likely the case in this school bus crash. While Keenen Clark may have an opinion he is not an expert in injury caution and his understanding of what caused his injuries is in error.

Never-the-less the issue of whether seat-belt use by children on school buses is an important one and not easily or clearly resolved.The authors of the CBC study suggested that Transport Canada deliberated hid the the fact that seat-belts on school buses could have prevented many injuries and deaths. That statement is true but it is also false. It is false because it fails to underline the important cautions in the Transport Canada study: that seat-belts can also be the cause of injuries and fatalities to children. The CBC authors failed to understand and properly inform the public just how precarious it is to restrain children of various sizes and ages into standard seat-belts than may not properly accommodate their anatomy. Even if there was a properly trained adult on board a bus who could initially place a seat-belt into a proper position on a child, anyone ought to know that children will not stay seated in an ideal posture for any extended time. Yet this is what is needed to ensure that the restraint system will function as it should. The CBC authors failed to understand why it is that booster cushions are required for certain ages of children – precisely because adult restraint systems do not fit a child properly. The authors fail to understand the large danger when the lap portion of a restrain system is not sufficiently tight and is not positioned below the child’s illiac crests (the frontal bony structure of the pelvis below the soft abdomen). Those who are familiar with injury assessment and seat-belt effectiveness know the tragic results when a child suffers fatal abdominal injuries in relatively moderate crashes because the lap belt was not in a proper position and the child “submarined” under the lap belt. The installation of 3-point restraints will not guarantee that such submarining will be prevented as the primary issue is the initial position of the lap with respect to the pelvis and the ultimate geometry of the restraint system.

I am not surprised that Transport Canada officials remained tight-lipped about discussing their findings or that they appeared to be hiding their research results. I am certain that they are aware of the dangers that could be introduced if un-monitored seat-belt use became prevalent on school buses. It would only require one incident where a school bus sustained an impact involving a major change-in-velocity and the bus was fully-loaded with a wide array of children of different sizes “wearing” their seat-belts. We would see the tragedies that would unfold. Numerous children would suffer abdominal injuries, some of these fatal, and there would be an outcry about the dangers of seat-belt use. If you could pick which collision a bus would be involved in then it would be simple to select the safety measures that could protect the occupants. But reality is not like that. Knowing the dangers of mis-used seat-belts researchers attempted to minimize the problem by introducing the idea of compartmentalization, that is, keeping children within the confines of where they are seated and using designs to minimize the injuries resulting from children being “bounced around” during an impact.

What the CBC authors failed to understand is that there has been substantial research into identifying the typical collision in which a school bus is likely to be involved. While not fool-proof such research has identified that in most cases a large school bus is more likely to be involved in an impact with a smaller vehicle such as a passenger car or light truck. Therefore the expected change-in-velocity of the bus is likely to be low because of the large mass difference between the striking vehicles. Seat-belts are helpful in reducing the forces in such larger changes-in-velocity but they are of less need for lower severity impacts such as rollovers. Rollovers can be dangerous if occupants are ejected however they can be of moderate injury potential if occupants are confined within the cage of the vehicle interior because in a rollover the change-in-velocity is very gradual and far less severe. Yes, children can be injured while tumbling inside a bus that is rolling over but this is a matter of severity of injury. It is the difference between sustaining lacerations, contusions and less severe concussions from tumbling versus sustaining potentially massive tears of major adominal organs from a mis-positioned seat-belt. When multiple children sustain those major injuries it would be virtually impossible to transport them in time to surgery and deal with those injuries when there are immediate requirements of multiple patients and only a limited number of surgeons. These are the types of complex issues that are involved.

I have no doubt that researchers have explained the issue to administrators at Transport Canada and these persons recognize that they car caught “between a rock and a hard place” such that there are no easy alternatives. The issue of abdominal injuries caused by seat-belts has been a difficult one even for adult occupants. When there is no easy solution yet you are the administrator or researcher who must make a difficult decision it is often believed to be best if the problem is not discussed. Thus the reason for Transport Canada’s apparent silence. Full disclosure of the real problems is complicated when the explanation requires a substantial technical understanding of the details that cannot efficiently passed onto a public that has a short attention span and is more interested in an explanation that is simple and fits their biases .Thus when these issues are often misrepresented to the public there is no guarantee that the correct message will be delivered as it should be.

While I am not in a position to know for certain, a compromise might be reached with improving the compartmentalization of children by equipping school buses with air bag curtains much like those in passenger cars. This might improve the chances that children might remain contained inside the school bus interior when it is involved in a side impact or as it rolls in a typical, lateral fashion. I am certain that researchers more familiar with the issue have already thought about this possibility. The potential costs of fitting a large school bus with sufficient lengths of side curtain and the subsequent costs of re-fitting a school bus after the bags go off would appear to be major drawbacks to this idea.

Regardless, this discussion outlines the extreme importance of conducting thorough documentations of school bus collisions by unbiased experts who can also properly and fully pass the results of those investigations openly to whoever needs to know. This is a continual problem that prevents many safety issues from being resolved promptly and efficiently.