Snow and poor visibility this past week has demonstrated the importance of speeding up the installation of automatic emergency braking (AEB).

Results of a multi-vehicle collision on Hwy 401 near Milton on February 13, 2019. (Courtesy of OPP Twitter)

A number of multi vehicle collisions have occurred on the 400-series expressways of southern Ontario this past week. These highways carry the most traffic volume at the highest speeds. Although weather forecasting can provide general information about conditions in a general area. However it is of minimal help for drivers who need more detailed information and about conditions in their immediate vicinity and where they are headed. Until vehicles of the future are equipped with weather and road surface “radar”, or technology that can warn drivers of the immediate conditions, weather related crashes will continue to evolve into dangerous, multi-vehicle pile-ups as unaware drivers crash into stopped vehicles from previous crashes.

Until vehicle-to-vehicle and vehicle-to-infrastructure expand into wide-spread and reliable systems, there is current technology available that could be the stop-gap solution. That technology is automatic emergency braking (AEB). AEB technology can “see” things ahead that drivers cannot, and automatic brake application could prevent or reduce the numbers of multi-vehicle pile-ups in poor visibility and poor road surface conditions.

This is particularly so in the wintry environment of high speed expressways that carry a large percentage of heavy truck traffic. What is often overlooked in that heavy trucks pose a particular problem in winter storms on high speed expressways. Firstly the drivers of these trucks cannot stop as quickly as drivers of passenger cars.

Inability to bring a heavy truck to a full stop is not the only relevant issue. But in many instances the drivers of light vehicles will “zig and zag” between these trucks at close range. Truck drivers cannot be continually applying light braking for every light vehicle that encroaches into their space. This results in many instances where a heavy truck is too close to a light vehicle. When heavy braking is required instability from collision avoidance can occur. Even if the truck driver has successfully avoided the first and immediate threat that may not be the end of the proble. A chain reaction of other emergency motions by other drivers to avoid truck now increase the probability that one of those drivers will be unsuccessful and a collision occurs. What happens next is often a game of rolling the dice as to whether this becomes a multi-vehicle, fatal consequence.

New technology might help if it could produce a warning or even prevent the driver of a light vehicle from encroaching into the dangerous space around a heavy truck. Whether such technology is possible could depend on the consequences from such  a preventative action. Even if such a feature was feasible it would require some advanced logic and this is not likely to be available in a short time frame.

So AEB provides the most logical and quickest way to affect traffic in the immediate future. The question of its reliability in the vast number of unique collision scenarios must always be tested with adjustments made from that experience.

Highway 401 near Milton, February 13, 2019. How many of these multi-vehicle pile-ups could be avoided or reduced through AEB?

The installation of AEB on heavy trucks would be highly desirable. A heavy truck travelling a highway speed poses a large amount of kinetic energy that has the potential of causing a lot of damage and harm. So if that kinetic energy can be controlled at its earliest stage great benefits are possible. The results might be analogous to the safety benefits of early ride-down provided to occupants by seat-belts. Unknown to many, it is the early “catching” of an occupant’s body by a seat-belt, which is attached to the vehicle’s structure, that provides a great safety benefit to an occupant. So too with a heavy truck, where an early detection of a problem, resulting in a early reduction in kinetic energy through brake application,¬† could provide the safety benefit, not only to the truck driver but to any occupants of other vehicles that could be struck by that heavy truck.

Thus reliable AEB cannot come quickly enough as it is likely to provide a substantial safety benefit by reduced the frequency and severity of multi-vehicle crashes on high speed expressways.