The first Session of the Colborne Street Traffic Study has been completed and partial results will be reported in this article.
in the late summer of 2022 the City of London Ontario announced that it would extent the cycling lane on Colborne Street north of Oxford Street to Cheapside Street. A protected cycling lane had previously been installed on Colborne south of Oxford. However the City proposed that the new cycling lane north of Oxford should not be protected. Instead the lane should be designated by a painted white line only. Cyclist and some members of the public objected to this decision as it would cause unsafe conditions for cyclists. Gorski Consulting was approached by interested members of the public whether a traffic study could be performed to evaluate the issue. As a result a series of video documentation sessions was commenced. The first Session was conducted on September 20, 2022. The results obtained from this session will be the focus of this article.
The City of London reported that its decision was in compliance with the guidelines offered in Book 18, Cycling Facilities, of the Ontario Traffic Manual. In part Book 18 provided a graph relating vehicle speed and volume that could be used to estimate what kind of cycling lanes should be provided. This graph from the June 2021 version of Book 18 is copied below.
This graph is slightly different from pervious versions. For example a similar graph from the 2014 Version of Book 18 is copied below. One of the differences between the two graphs is that in 2014 the “85th Percentile Motor Vehicle Operating Speed” formed the vertical axis whereas in the newer version the vertical axis is the “Posted Speed Limit”. In the text of the June 2021 manual the authors advise that the 85th Percentile Speed can be used when data suggests that the operating speed is higher than the posted speed.
In speaking briefly with a representative of the City of London at an information meeting it was stated that the City of London did not conduct any specific studies on Colborne Street and mainly relied upon the traffic volume in their decision to select the painted cycling lane. A handout provided at the meeting indicated that the traffic volume in the corridor was between 4000 and 6400 vehicles per day.
A copy of the traffic volumes taken from the City of London map is shown below. This shows that the traffic volume (AADT) between Oxford and St James is 6500, whereas the volume between St James and Cheapside is 4500. So there is a marked reduction is traffic north of St James. It suggests there is likely exit of Colborne Street by many northbound drivers onto St James. And there could also be a likely entrance from St James southbound onto Colborne Street. Either way it suggests there is a considerable interaction of traffic at the Colborne and St James intersection.
While the above graphs are not the only information needed to select a proper cycling facility they represent major inputs in the process. Knowing the specifics of the operating speed and traffic volume are key points in using the guidelines. As such video documentation at the Colborne site would provide valuable data the selection process.
Session #1 of Colborne – St James Traffic Study
Selecting the location of the study needed some consideration as the operating speed should be documented in a location where vehicles are moving at a constant, uninterrupted rate. Selection of a location where vehicles are stopped, turning, accelerating or braking does not provide a true indication of the speed of vehicles on the road. The best location appeared to be away from the busy area at Oxford Street and also away from the end of the proposed cycling lane at Cheapside Street. It also needed to be away from the motions occurring at the St James intersection.
The final decision placed the documentation just north of St James. The Google Maps view below shows an overall view of the Colborne and St James intersection. The “Zero” location of the documentation is shown as 15 metres north of the north curb of St James. It can be noted that a pedestrian crossing existed on the south side of the intersection and this caused an interruption in the normal traffic flow. Also a bus stop was located further south which also caused some interruption.
Speeds and traffic volumes were documented over two, 50-metre segments north of St James. At this initial stage it was decided that only northbound traffic would be documented and that southbound data would be obtained from analysis of the video at a later date.
The Google Maps view below is looking northbound on Colborne Street from just south of the intersection with St James. The northbound bus stop can be seen on the right side of the view (blue sign on pole) and the pedestrian crossing is also visible in the background.
The next Google Maps view below is looking southbound from just north of the St James intersection. There is a fire hall located on the south-west quadrant of the intersection. Also note the rather wide boulevards located on each side of Colborne. Our measurements indicate that the east boulevard is 5.2 metres whereas the west one is 4.9 metres.
It can also be noted that the southbound lane is much wider than the northbound lane. Our measurements indicate that the southbound lane is 6.1 metres wide whereas the northbound lane is 3.85 metres. This difference is because parking is allowed along the west side of Colborne. In the handout provided by the City (copied below) the proposal is that the west side parking lane will be removed. Two 3.3-metre wide lanes will be created for motor vehicle traffic and then 1.7-metre wide cycling lanes will be created on each side of Colborne. It would appear that the boulevards (i.e. painting strips) will remain as they are without any widening of the road.
With the existence of a city-transit bus route there is concern about the proposed 3.3-metre-wide lanes which are narrower than the 3.5-metres, or wider, that would typically be seen. A city transit bus would be in the neighbourhood of 2.6 metres in width and this would cause a gap of only about 35 centimetres between the side of the bus and the left and right edges of the lane. Given the propensity for motor vehicles to stray from a perfectly aligned position in a lane and given the similar propensity for cyclists to wander left and right as they balance the cyclists, there is an increased likelihood of possible contact between these units. Even slight contact of a cyclist or cycle can create considerable problems to the safety of the rider.
Session #1 – The Results
The image below is a frame taken from the Premiere video project showing the synchronized output of six video cameras. It can be recalled that average speeds are obtained by noting the time taken for a vehicle to travel over a 50-metre distance segment. It is a simple process to take the 50-metre segment and divide it by that time to arrive at an average speed in metres-per-second (m/s). Metres-per-second are then multiplied by 3.6 to transfer to kilometres-per-hour (km/h).
Documentations commenced at 1020 hours on September 20, 2022 over a period of one hour.
The table below shows the results of the documentations of northbound cyclists. Only 15 northbound cyclists were observed during this time. Only three of them were females. The fastest speed was at Observation #8 where a male rode a road bike at an average of just over 28 km/h. The slowest speed was at Observation #7 where a female rode at an average speed between 14.8 and 15.7 km/h.
The overall average speeds of the cyclists was just over 22 km/h in both segments of roadway. This is somewhat high compared to speeds on other cycling facilities such as the Thames Valley Parkway and none of the 15 cyclists appeared to be riding an e-bike. Yet it is not unusual for situations of uninterrupted travel where cyclists do not need to slow for pedestrians and other obstructions.
The next table shows the results of the motor vehicle volumes and speeds. Each cell shows the observation number followed by the speed in km/h up to two decimals. As an example, the first observation fell into the 41-45 km/h column and can be seen at the very bottom of the table. The “1-44.75” means that the precise speed of the vehicle in Observation #1 was 44.75 km/h.
A total of 136 observations of motor vehicles was made. Eighty-five percent of 136 is 115. So in determining the 85th Percentile Speed we need to find the value of the 115th observation. it is a simple process of adding up the frequencies in the columns up to the speed range of 46-50 km/h, arriving at a cumulative frequency (4+4+30+34+38 = 110) of 110 observations. We now need to find the 5th slowest observation in the column of speeds 51-55 km/h. That 5th observation shows a speed of 51.10 km/h and therefore this is the 85th Percentile Speed.
A similar process was conducted for the second road segment, between the 50-metre and 100-metre markers. This analysis showed that the 115th observation contained a speed of 51.87 km/h and so this was the 85th Percentile Speed for that distance segment.
Not enough analysis has been completed at this time to obtain an estimate of the motor vehicle traffic volume since only northbound vehicles were documented. A temporary (though possibly errored) estimate could be obtained by multiplying the 136 observations by 2. Thus we might estimate that a total of 272 motor vehicles passed by the area in one hour. If this was the peak hour then we might estimate the AADT by multiplying by 10, resulting in an estimated AADT of 2720. However the counts were taken between 1020 and 1120 hours and this would clearly not be the peak hour. So based on the present data we can only say that the AADT at the site is higher than 2720.
Another approach is to accept the City of London traffic volume data which was estimated to be about 4500 AADT. Combining this with the 85ht Percentile speeds (about 51 to 52 km/h) we can look at the graph of speed and volume prepared in Book 18, shown previously.
Two additional Sessions have already been conducted on September 30th and October 5th and the data from these Sessions are in the process of being developed.
Session #2 on September 30th was undertaken for two hours, between 1612 and 1812 hours. This session would include the peak hour. At time of writing a total of 443 northbound vehicles have been documented, or about 222 per hour. This is almost twice as many vehicles per hour than an in Session #1. Further details from this Session #2 will be revealed in a separate article shortly.