We have all seen it. The battles of the expressway construction zone. But rarely do we discuss it. The battles and dangers that exist in the line-ups approaching construction zones on high-speed expressways are something that is rarely discussed or detailed.

As part of our ongoing safety research Gorski Consulting has conducted a detailed examination of the actions of drivers within a line of stopped/slowed traffic approaching a construction zone on the Highbury Ave expressway near Commissioners Road in London, Ontario, Canada. Previously testing was conducted at this site on April 7, 2020 and reported in an article (“COVID-19 Effects on Highbury Ave Traffic – Review & Discussion of Data”) posted on this website on April 11, 2020. That article provided details of the change in traffic volumes and speeds compared to a previous testing date in November of 2019. The April 7, 2020 occurred just prior to the commencement of construction to re-build the bridge over the Thames River a few hundred meters north of the testing site. The Googlemaps view below shows the location of the construction site with respect to the location of the testing site. The distance between these locations is about 1.1 kilometres.

Below are several views travelling south along Highbury Ave from the bridge construction and showing the Commissioners Road overpass in the background. All these photos were taken on July 16, 2020.

Below are several views while travelling north on Highbury Ave, past the testing site, and through to the construction zone at the Thames River bridge. All these photos were taken on July 16, 2020.

As typical, the testing on July 15, 2020 involved set-up of multiple video cameras in a 400-metre zone, 200-metres each to the north and south of the Commissioners Road overpass. Some cameras were positioned on the overpass facing north and south.

Below are several views from one of the cameras on the overpass, facing north and showing the conditions of the northbound lane just after 1600 hours. The scenario shown in the views is typical of what happens when the right lane becomes clogged with traffic and the left lane is free and clear. It has been customary for drivers to pull into the right lane early so as not to have problems trying to squeeze into the lane when the left lane is closed in the distance. However some drivers use this as an opportunity to use the left lane to pass all the stopped traffic resulting in irritation from those drivers in the right lane. The result is that some drivers, often those with large and heavy trucks, will pull out and block the left lane in order to stop those drivers using that lane to pass stopped traffic. This is what is shown in the sequence of photos below.

This is typical of the trench warfare that continues on a daily basis on approaches to construction zones. The Ontario Ministry of Transportation has commented that drivers should use a “zipper merge” procedure in heavy traffic such that both lanes should be populated up to the location of the closed lane. At the point where the lane closes drivers are supposed to alternate merging into the remaining lane. While this may work in theory the practical reality is that drivers have difficulty waiting until the last possible moment to change lanes when it is left to the cooperation of other drivers to “let them in” to the only available lane. Timing of the lane change is also difficult for drivers to grasp with respect to the end of the closed lane and the differences in speed of traffic also make this lane change challenging. The result is that there are many conflicts that occur, some leading to potentially dangerous outcomes.

There are many challenges that exist on expressways involving stopped or slowed traffic which will be discussed in other upcoming articles on this website.