This article is a continuation of reports regarding the passing motions of motor vehicles as they approach cyclists from behind. It has been noted in several previous articles that a single article is dedicated to each observed passing motion on Colborne Street in London, Ontario. This data was collected through video recording sessions on April 12, April 14, and June 8, 2023. Fourteen instances of such passing motions were documented and these are shown the table below.
The present article is focused on the observation labelled “Jun 8 – 8”. In this incident a Dark Grey SUV passes a cyclist at the 30-metre marker of the 50-metre observation zone. The lateral position of the cyclist who travelled through the observation zone is shown in the table below. The lateral position is with respect to the edge of the concrete gutter at the right side of the northbound lane of Colborne.
As can be seen in the above table the cyclist has travelled through the site at an average distance of 0.56 metres west of the concrete gutter. This position is relatively close to the gutter and closer than the typical position of cyclists.
Th figure at the top of this article shows the cyclist at the timecode 01;21;41;08 as the cyclist is passing the Zero marker at the south end of the 50-metre zone of observation. The next figure, below, shows the situation at timecode 01;21;43;22, as the Dark Grey SUV crosses the Zero marker. At this time the right front tire of the SUV is located 2.10 metres west of the concrete gutter.
in the next figure, below, at timecode 01;25;45;24 we see the situation as the cyclist is crossing the 25-metre marker and the Dark Grey SUV is approaching closely behind. The orange markers only extend to 2.00 metres from the concrete gutter and it can be seen that the SUV is beyond that distance, and its left side is to the west of the roadway centreline.
In the next figure, the timecode is in error and should read 01;21,45;53. The SUV is seen crossing the 25-metre marker while the cyclist is just ahead of it. We noted that the right front tire of the SUV was located 2.50 metre west of the concrete gutter. Given that the cyclist was positioned 0.60 metres west of the concrete gutter this provides the evidence that the SUV driver has chosen a path that is well beyond the 1.00 metre requirement under Provincial regulation.
In the next figure, below, we see the situation as the Dark Grey SUV crosses the 50-metre marker at timecode 01;21;47;44. At this time the right front tire of the SUV is located 2.50 metres west of the concrete gutter. This lateral location is more than sufficient since the cyclist is still approaching the 40-metre marker and is located about 0.55 metres west of the concrete gutter.
In the final figure below we see the cycle’s front tire crossing the 50-metre marker at timecode 01;21;49;43 and the tire is riding over top of the junction between the asphalt lane and the longitudinal edge of the concrete gutter. While it is advisable to maintain a lateral location that is a far to the right as possible, it is not safe to ride over a longitudinal junction like this because it can quickly cause a loss of cycle control. This is one of the problems with the advice provided in Book 18 of the Ontario Traffic Manual which stipulates that cycling lanes can be as narrow as 1.50 metres and this width includes the concrete gutter.
As in previous articles we can conduct further analysis of this scenario by examining the lateral and longitudinal positions of the traffic units.
For example we can calculate the average speed of the cyclist. It took the cyclist 4.48 seconds to travel the 25-metre distance from the Zero marker to the 25-metre marker. This is an average speed of 5.58 metres per second or 20.09 km/h. In the second part of its travel to the 50 metre marker it took 4.10 seconds to travel the 25-metre distance or 6.10 metres per second or 21.95 km/h.
We can also calculate the speed of the Dark Grey SUV. In the first 25 metres the SUV travel the distance in 2.35 seconds or 10.64 metre per second or 38.30 km/h. In the second half of its travel it covered the 25 metres in 1.85 seconds or 13.51 metres per second or 48.65 km/h.
Overall the Dark Grey SUV maintained a reasonable lateral distance away from the cyclist while the passing motion occurred. At the Zero marker the SUV was 2.10 metres away from the concrete gutter, this increased to 2.50 metres at the 25-metre marker and this lateral distance was maintained at the 50-metre marker.
As noted in previous articles, the reason for this detailed study of passing motions is that we want to see how the installation of a painted cycling lane changes the passing motions of motor vehicles and the cycles that are being passed. Once the painted cycling lane is created it is hoped that another series of video sessions will document additional passing motions . There is no guarantee of what results may occur. But it is an important exercise to complete such work given the large number of instances where cyclists are stuck from behind by passing motor vehicles yet there is no objective data to determine how and why this happens.