Transport Truck Collisions In Winter: A Demonstration of Expressway Safety Problems

Poor weather, large numbers of heavy trucks and a lack of safety education are a toxic mix on Ontario’s expressways. This has been made apparent again when a winter storm passed through southern Ontario in the past couple of days. Police posted warnings before the storm and they posted warnings during the storm: “When you see snow go slow”, and similar sage sayings.But that did not stop the sharp increase in collisions that occurred. And these increases occur every time a winter storm passes through. By now it would seem that the broken record has been playing the same tune too long and it’s time to change the record.

Rather than calling the same tune is it not wise to admit that something keeps reoccurring and that an understanding is needed why we cannot stop massive numbers of collisions in winter storms? Every year well over 200,000 collisions are documented and sent to Ontario’s Ministry of Transportation. Various sensors are imbedded in roadways that monitor traffic. Traffic cameras are increasing in exponential numbers. All this information seems to be deposited into a black hole  with no chance of coming back out to the public that needs it.

The safety information provided on the Gorski Consulting website is one of the  few independent sources that is not involved in this all-encompassing vortex. While the views expressed may not be shared by all, an attempt is made to provide objective facts and remain  unbiased.

What is observed is that winter storms and heavy truck transportation are a particular problem on Ontario’s expressways. Even on pleasant days with dry road surfaces and clear visibility the drivers of heavy trucks are at a disadvantage due to their lessened ability to brake, difficulties in seeing everything around them, and the simple fact that the very large masses they haul can potentially have devastating consequences to them and those drivers around them.

Highway 401 is perhaps the best example of these problems as it is the longest expressway in Ontario, stretching well over 800 kilometres between Windsor and the Quebec border. Very large percentages of trucks use this highway. And high percentages of these trucks are on long-haul missions that take them to all parts of North America.

When truck drivers travel long distances in winter, without many stops, they can approach a weather system and pass through it, experiencing various environmental changes that are important to their safety. It would not be unusual for example, for a westbound truck driver to enter Highway 401 at the Quebec border and experience sunny and dry conditions. But storms that approach from the west can sometimes travel as fast as the trucks themselves. Thus the closing speed between a westbound truck and a storm can be at 200 km/h. This rapid approach means that highway conditions can change rapidly. Our westbound trucker at the Quebec border could experience a severe winter storm by the time he reaches Kingston, which is just over 200 kilometres away, even though the storm might have been in Toronto when the trucker entered Ontario. And that storm might lose most of its effect by the time the trucker reaches London which is another 200 kilometres to the west of Toronto. While it is easy to say that one must drive for the road conditions, when those conditions change rapidly, not all drivers will detect deteriorating conditions at ideal times.

Due to the very large numbers of units involved it only takes a few drivers who misinterpret the conditions for the creation of a potential safety nightmare. Traffic volumes are below 20,000 units per day near the Quebec border, they increase to over 400,000 through the centre of Toronto and they fall back to below 20,000 again in some parts approaching Windsor. A misinterpretation by just 1 in 200,000 drivers could result in a major catastrophe. Yet how many of us, in whatever task we may select, have failed to perceive something or failed to perform a task properly that we have done 200,000 times previously with success? In fact a success rate of 199,999 times in 200,000, would seem to be very good. Yet in the deadly environment of traffic conflicts many of us perceive this as horribly inadequate.

Winter storms change road surface conditions and we refuse to admit that those changes are sometimes difficult to detect. In the early onset of a storm the small quantities of snow that fall on a road surface can change the tire force dramatically. In one instance temperatures and minimal wind can create a wet surface with a co-efficient of friction in the range of 0.5g. Alternatively, a slightly colder temperature with higher winds can change that surface to an icy mix that is not consistent along the length of the highway. Icing becomes sporatical depending on local characteristics where elevation changes and exposure to wind drop the co-efficient of friction below 0.2g. In comparison the same surface in dry conditions might provide a value in the range of 0.6g for trucks. Is that important?

With maximum braking on a dry surface with 0.6g, a truck with a fully functioning braking system will stop from a speed of 100 km/h in just slightly less than 80 metres. Under the same scenario but a co-efficient of friction of 0.5g, the same truck would need slightly less than 90 metres to come to as stop. But on an icy surface that has a co-efficient of friction of 0.2g, a distance of about 200 metres is needed to come to a stop. This difference is dramatic.

What we fail to ask is whether a truck driver can easily detect the difference between wet and icy road surfaces. In both instances there could be snowfall or snow accumulated on roadsides. But in the vicinity of where the truck’s wheels travel, within a lane, the road surface could be bare of such snow. What may remain is a dark asphalt surface that could either be wet or icy. Both conditions could cause reflections of light into the driver’s eyes where that light needs to be processed and an understanding needs to be made. So is that easy to do? In our view the answer is no in a significant number of instances. Enough so that misinterpretation of surface conditions is a common occurrence in winter driving.

We can combine these road surface problems with issues of poor visibility. Every driver has experienced those winter situations where snowfall or even strong winds can produce white outs. But even less intense scenarios can be problematic. Even in good weather, without additional and specific cues, drivers have difficulty detecting the speed of vehicles that are ahead of them by more than about 175 metres. Once a slow-moving vehicle is detected there no guarantee that the precise speed will be known, only that the vehicle may be moving slowly or stopped. But that encompasses a very wide range of possible speeds. A speed of 80 km/h would be considered slow for a typical expressway. But even in poor weather conditions most drivers drive faster than advisable. Under these conditions truck drivers expect other vehicles to be going at least 80 km/h but not 40, or stopped. And hazard lights are not always activated. Yet early detection of slowed traffic is more important for truck drivers than for drivers of smaller vehicles that have more efficient braking systems.

We can combine a further problem with the road surface condition and the visibility problems: The incompatibility of trucks and small cars. Many car drivers do not appreciate the limited visibility that is available to truck drivers. A truck driver that wants to make a lane change must look a long distance behind the truck trailer to evaluate whether his truck may interfere with a car that is approaching from behind often at a much higher speed. Heavy trucks can require as much as 10 seconds to make a full lane change and in that time the truck could travel close to 300 metres. A car travelling at 130 km/h travels about 36 metres every second, so in 10 seconds it could travel about 360 metres. Thus, even from a long distance back, the speeding car driver could reach the back of the truck’s trailer long before the truck has had a chance to complete its lane change. It is no wonder that some speeding car drivers think that truckers are intentionally interfering with their right to speed.

Another problem in three-lane traffic is that many long-haul truck drivers become fed-up with constantly weaving in and out of the slow (right) lane as vehicles merge from entrance ramps or slower trucks are encountered. So they will purposely drive in the middle lane where there is less interference. But when the right lane is open many car drivers will use that lane to pass a truck especially when the fast lane is crowded with traffic. A number of dangers develop from this situation. First of all car drivers do not fully see the length of the slow lane ahead when they steer into it from behind a long and wide truck. Unexpected slow vehicles, or even vehicles that have encountered an emergency might be stopped in the lane without being detected in time. Any impact involving other vehicles has a good chance of involving a nearby heavy truck simple because the length and width of the truck takes up some much of the highway.

We have all been exposed to the Move Over law which requires drivers to move away from a lane or shoulder where an emergency vehicle may be stopped. When car drivers drive into the right lane from behind a truck they may not detect emergency vehicles even with all the emergency lights being illuminated.

There is also the common problem that truck drivers have poor visibility of small cars that are located near the road tractor’s right front wheel or just in front of the road tractor’s right front corner. A number of collisions occur where the truck driver claims that he did not see any vehicles when he steers into the right lane.

Further problems exist because heavy trucks are so wide and they are buffeted by winds causing trucks to move out of a lane. Although the travel lanes of expressways are extra-wide, usually about 4.0 metres, a heavy truck that is about 2.6 metres wide must use that lane just like a small passenger car that may be only 1.5 metres in width. When large gusts of wind come small cars are often of a more aerodynamic design that prevents them from being blown from side to side. That is not the same for heavy trucks that may be hauling empty, 52-foot long, semi-trailers. Such trailers have little design to reduce their being blown out of a travel lane. The problem with this should be obvious.

And the final issue that will be mentioned in this article is the one of lane closures from road construction or emergency road operations. When lane closures occur on busy expressways the highway may become clogged up for many kilometres back from the actual lane closure. The most dangerous time is when vehicles are approaching the back of the que of stopped vehicles. Although truck drivers sit higher off the ground and therefore are able to detect stopped traffic ahead sooner, sometimes those trucks are travelling very close behind each other and visibility ahead is almost non-existent. When a truck driver brakes suddenly others behind may not react quickly enough such that the braking of the following truck becomes more severe. It does not take much thought to understand that the third or fourth or any other truck further behind may not be able to stop even when applying maximum braking. Thus a rear-end impact occurs. And that rear-end impact can make problems worse as other truck drivers further behind have little time and distance to detect that an impact is occurring because they are also too close behind the truck ahead. Some of the worse multi-vehicle pile-ups occur from this type of scenario. The installation of Automatic Emergency Braking on heavy trucks would be of great benefit in so many of these scenarios. Yet governments are slow in making this mandatory.

While adding additional lanes and concrete median barriers can help in some expressway situations, the fact is that these will not stop many collisions from happening. What is needed is a thorough and detailed study of traffic on expressways to understand what conflicts exist and this leads to the final comment in this article.

Policy-makers in Ontario have created some bazaar and dangerous situations, perhaps because they have spent too much time examining the contents of large traffic databases and not understanding that some real-life conditions are not accurately reflected in large scale data.

Strange as it may seem the purpose of creating inaccurate data is not always benign. Inaccurate data can be of benefit to those who are required to take action when a real-life problem exists, but that problem is masked by the existence of inaccurate data which demonstrates that no action is required. Hiding traffic data or making that data inaccurate can be a benefit to those who may be held accountable should good and accurate data reveal their inappropriate actions.

Traffic conflicts can be represented by a pyramid where the small number of fatal collisions are at the very peak. Below are a larger number of injury-producing collisions that are still very small in number compared to the overall number of conflicts. The much large number of collisions are those reportable ones where injuries do not occur. But many of these reportable collisions are only reported to a Collision Reporting Centre and the report contents are based on the verbal or written information provided by the involved drivers. This makes for poor or no information being gathered about the causes of many of those large numbers of reported collisions.

At the bottom of the pyramid are those vast numbers of incidents and collisions that never make it to the Ontario Provincial statistics. These are collisions of less monetary loss that are often single vehicle incidents where there is only one driver and no one else involved. Research by Gorski Consulting suggests that these unreported incidents could be well over 80 per cent of all collisions or incidents, or that less than 20 per cent of the full number of collisions or incidents are ever reported. Many argue that these incidents are meaningless as their results are of little consequence. Yet the fact that the incident occurred could illuminate a safety issue that has not yet reached the level of causing a more serious incident and so these non-reported incidents could be the canaries in the coal mine.

The reality is that Provincial and Federal data files of collisions are often incapable of detecting certain safety issues because they do not contain the much larger number of incidents of a minor nature that occur in official blindness. When analysts examine a reported collision they do not have information about 8 or 9 others that have also occurred but have not been officially documented. Even though very large numbers of collisions are reported every year, they are all taken from a small slice of the overall pie, and each year the same slice is sampled from the same part of the pie. What exists in the rest of the pie unknown.

Let us use this simple analogy. A restaurant owner wishes to serve a pie to his valued customers and always slices a piece off for his personal testing and evaluation. Meanwhile the baker has mistakenly placed pepper in a specific area of the pie which is never sampled by the owner. A random slice of the pie is sent off to the customers who, tasting pepper, are outraged and never return to the restaurant. In the traffic case the owner (Provincial government) does not care whether the customer comes back because the government has a monopoly on dishing out pies to all its citizens. So you either eat the Government’s pies or you do not eat at all.

But we should have an option to change this. The public should have the right to sample the whole pie and not just at the same spot but where ever the public choses. We can take action to remove the “pepper” in our collision statistics. That should be our democratic right.