Do we understand what these signs mean? Or are we just ignoring them?

The City of London Ontario has put up some interesting “Zipper Merge” signs in the construction zone on Highbury Ave. The signs are supposed to encourage drivers to use a “zipper merge” technique that, so far, has been ignored by Ontario drivers.

Below is a frame taken from video during observations of traffic at the Highbury Ave site on September 3, 2020. The green “Zipper Merge” signs can be seen posted along the median of the highway but almost all drivers continue to use the right lane. When a vehicle tries to use the left lane, as shown in the frame below, vehicles, particularly large trucks, will pull out and block the left lane preventing “speeders” and “cheaters” from taking advantage of the left lane to pass the slow or stopped traffic.

The trench warfare continues at the construction site on Highbury Ave, south of Hamilton Road in London, Ontario. Even though green “Zipper Merge” signs have been installed to encourage drivers to use both lanes up to the point where a closed lane ends, drivers continue to stay in the right lane. Many drivers, such as the driver the large truck in this view, purposely pull into the left lane to block any drivers attempting the use the left lane to speed past slow or stopped traffic.

The extent of exclusive usage of the right lane is obvious in the two additional frames shown below.

There are many problems that develop during this warfare, some that become dangerous. When the left lane is free of traffic the few vehicles that use that lane will travel at very high speeds because of the 100 km/h posted speed. This speed occurs just next to traffic that may be stopped in the right lane. At times drivers in the right lane decide to pull out of the right lane into the left lane, sometimes from a dead stop. This leads to very dangerous differences in speed that could lead to high speed crashes. This is just one of the problems that exists in construction zones that is not discussed.

Gorski Consulting has been monitoring the construction zone on Highbury Ave in London this past summer to gain some insight into some of the factors that lead to collisions in expressway construction zones. We hope to post additional articles on this issue on the Gorski Consulting website in the coming weeks.