The installation of a High Tension Cable Median Barrier (HTCMB) in the 118 kilometre distance of Highway 401 between Tilbury and London Ontario has been controversial in that some groups have been lobbying for the installation of a concrete, Jersey-type barrier as exists along the rest of the super-highway throughout southern Ontario. The reporting on the latest truck collision that resulted in a median crossover  is lacking in the clarity that is needed to properly inform the public on the performance of the cable barrier.

In an article by Laura Broadley of the St. Thomas Times-Journal newspaper the title read “Cable barriers stop transport truck from crashing through Highway 401 median”. The incident involved a westbound tanker truck carrying “flammable fluids” that passed through the median, struck the cable barrier and came to as stop partly in the north shoulder and partly in the eastbound passing lane of the highway just east of Downie Road. The only photo available of the incident is shown below. Red circles were inserted by Gorski Consulting from a previously posted discussion.

OPP photo with red circles highlighting points of interest.

The cable barrier was likely helpful in redirecting this tanker truck and may have prevented collisions with eastbound traffic. However the newspaper title indicating that the cable barrier stopped the truck from crashing through the barrier is obviously incorrect. The cable barrier was located only on the far (south) side of the median and therefore the truck made first contact with the barrier after it had already passed through the median.

Furthermore it was mentioned that two eastbound vehicles sustained “minor” damage from “colliding with debris from the truck and tension cables”. It is important to understand that even small debris can be dangerous when high speeds are involved. An eastbound vehicle travelling at 100 km/h striking a piece of small debris moving in the opposite direction at 50 km/h means that this debris could be striking that eastbound vehicle at a closing speed of 150 km/h. Debris that is small and/or narrow can make contact in a small location where the force may be focused in that small zone thus increasing the possibility that it might pierce through the structure of a vehicle. (The analogy of spear penetrating a warrior’s armour is not a bad example). This is particularly true of an impact to a windshield. Thus it is very important to explain what debris made contact and where that contact occurred on the eastbound vehicles. These details may appear trite until an incident occurs where someone is badly injured or killed.

Further analogies come from many years of examining head-on collisions where seemingly small and harmless objects have been stored on the back parcel shelf of a passenger vehicle. This parcel shelf is the flat area located under the rear window. A typical example is the installation of an after-market audio speaker which often contains a small but solid magnet.  Unsuspecting drivers do not understand that in a major frontal impact such an after-market speaker can become dislodged and can come flying at the head of an occupant and cause a serious head injury. This is not a comment made without experience but comes from years of study of occupant injuries with the University of Western Ontario Multi-Disciplinary Accident Research Team in London.

It is important to document such details of a collision not only because it explains what happened in this single case. It is important because the findings from such collisions will be used in the future by policy-makers in their decisions about what installations will work best. The reason why the current cable barrier was chosen for installation is because of previous studies conducted in Europe and North America where it is assumed that the reporters of those findings made properly detailed documentations of the relevant consequences. The experience documented along Highway 401 will also be used by policy-makers in other parts of the world. Thus it is a important matter to report these incidents properly.