Simply blaming the rear-ending truck driver for a severe impact will not protect anyone from the next tragedy. But an objective, detailed analysis will. Scientific study can illuminate unknown or hidden factors that might be corrected resulting in a reduced chance of a future occurrence.

A serious, rear-end impact occurred in the early evening of  July 5, 2019 in the eastbound passing lane of Highway 401 at the Iona Road interchange south-west of London, Ontario. The Ontario Provincial Police (OPP) displayed two photos of the two involved transport trucks on their Twitter account. These photos are shown below.

This OPP photo shows gouges in the foreground of the passing lane of Highway 401 where the initial impact occurred, and the two transport trucks stopped at the Iona Road overpass in the background.

This OPP photo shows the extent of frontal crash of the cab of the striking truck as it collided with the rear of the trailer of the other truck. The extent of structural intrusion into the occupant space of the crushed cab would be the primary, injury-causing factor as both occupants of the cab reportedly sustained life-threatening injuries.

It is estimated that the trucks travelled approximately 40 metres from impact to rest. A truck skidding from maximum brakiing would likely lose a speed of about 70 to 80 km/h in a distance of 40 metres. However It would be difficult to imagine that, if the first truck was fully-stopped, it could be pushed forward that distance without sustaining more visible crush to the rear of the trailer. Also, although the extent of crush to the cab of the striking truck is extensive, it does not appear to match the scenario of the truck impacting a stopped truck at a speed of 105 km/h. Thus the most likely scenario is that the first truck was likely travelling slowly in the passing lane when it was struck by the impacting truck which had already lost a substantial amount of speed before impact. This is the best that can be accomplished given that we do not have access to any site measurements or the full police photos that would normally be available in an official reconstruction.

Not unexpectedly, police and official news media provided only a scant reporting of the incident without the details that would be needed to understand how and why the collision occurred. What is known is that such collisions are not rare. In fact, in the recent history of the highway, they are becoming common. As drivers become accostomed to travelling long distances at high speeds without interruptions, a sudden slow-down of traffic is unexpected and drivers are not prepared for this violation of their expectations.

The common approach observed in many of the comments that appear on various public forums is to make judgments on the “stupidity” (and similar comments) of drivers who cause such crashes. Rarely are such comments accompanied by any detailed analysis or understanding of how and why the collision occurred. In many instances, such detailed analyses uncover important clues and result in better understanding of why such a collision occurred. Yet it is practically impossible for anyone to make such an evaluation because the base evidence is never available.

Trucks travelling this route may come from any part of Norh America, including Mexico. Attempts to improve driver habits often include publicity of police enforcement efforts on various local news outlets. Unfortunately these attempts can be of minimal use when drivers are passing through from vast distances where local news is not available to them.

While traffic slow-downs and stops may sometimes be unavoidable, they also need to be monitored and studied. One of the difficulties that shows on a regular basis is that drivers do not apply braking early enough, or hard enough, when it is needed. Lack of visibility ahead may be one of the crucial factors causing this problem. Large truck trailers become the walls that block the view of drivers of the road ahead and many drivers are accostomed to travelling very close to the rear of such trailers thus increasing the significance of the problem.

Automatic Emergency Braking (AEB) that is becoming more common on light vehicles is not likely to be installed on large trucks in the foreseeable future even though this technology is greatly needed. Thus, until that occurs, an important matter is to document those instances where traffic is slowed or comes to a stop and to evaluate whether there is something that can be done to warn drivers of that unexpected happening. Unfortunately actions such as these are not being discussed and serious rear-end collisions continue to occur without much public attention.