Results have now been tabulated for Session #2 of traffic observations on Colborne Street at St James Street in London, Ontario. This testing was conducted on September 30, 2022 for two hours between 1607 and 1807 hours. A total of 443 northbound motor vehicles and 19 northbound cyclists were documented during this session. The results are as follows.
Session #2 – The Results
The characteristics and speed of northbound cyclists observed during the documentations are shown in the table below.
Looking at the 443 documented motor vehicles, their average speed was 42.49 km/h in the south road segment (i.e. between 15 and 65 metres north of St James Street) and 44.13 km/h in the north segment (i.e. 65 to 115 metres north of St James). While these averages provide some clarity the details reveal more complex issues.
Firstly, the table below compares the frequencies of speed between the south and north road segments. Generally, the speeds seemed to be compacted into a narrower range in the south segment while those speeds along the north segment were slightly more scattered, with both lower and higher speeds.
The table below shows the relationship between motor vehicle volume and speed at 10-minute intervals while comparing the south road segment with the north road segment.
For example, in the first 10 minutes of observations (1607 to 1617 hours) 50 northbound vehicles passed through the observation area. The average speed of those vehicles passing through the south road segment was 39.96 km/h. The average speed of motor vehicles passing through the north road segment was 41.28 km/h. We can also note that in the first hour of observations the average speed of vehicles travelling through the south road segment was 41.95 km/h while the average through the north segment was 42.83 km/h.
There was a marked increase in motor vehicle speeds in the last 40 minutes of observations (noted by the red colour of the values in the above table). This would be a time between 1727 and 1807 hours. It can be noted that during this 40 minutes the average,10-minute, traffic volume was reduced to 32 vehicles whereas the average for the previous hour and twenty minutes was 39.4 vehicles.
It was noted that many traffic disruptions developed from the intersection at St James Street. Many motor vehicles entered Colborne Street from St James but also many motor vehicles exited Colborne at this intersection. As a result some consideration had to be given to the difference between “free flow” traffic on Colborne versus “non-free flow” traffic.
Of the 225 northbound motor vehicles that were observed in the first hour of documentation it was noted that 167 of them experienced “free flow” motion and their average speed was 43.14 km/h in the south segment and 43.54 km/h in the north segment. Of the 218 northbound motor vehicles that were observed in the second hour of documentation it was noted that 138 of them experienced “free flow” motion and their average speed was 44.97 km/h in the south segment and 47.28 km/h in the north segment. The reduced number of vehicles experiencing free flow in second hour should have produced slower average speeds yet this did not occur, particularly in the north road segment. So It may suggest something different about the speed of traffic in the latter portion of this testing.
A flavour for the types of obstructions to traffic on Colborne can be gained by examining the smaller sample of 57 northbound vehicles that experienced “non-free-flow” motion in the first hour of documentations and these are shown in the long table below. The observations high-lighted in yellow represent vehicles that entered Colborne from St James. Since documentation began only 15 metres north of the St James intersection the speed of these vehicles would have to be low as they would just be completing their turns. So this is the reason why we determined that they could not be counted as free flow vehicles.
As can be seen in the above table there were many reasons why the free flow of northbound vehicles did not occur. Another major reason was that pedestrians crossed at the pedestrian crossing located on the south side of the intersection with St James. As such northbound vehicles had to come to a stop and this caused their speeds to be slower as they passed through the south road segment.
A surprising revelation occurred as we were present monitoring the video cameras near the St James intersection. We observed unusual behaviors by many drivers who seemed to be confused by whether they had the right-of-way. For example, drivers on both roadways appeared to believe that this was a 4-way stop. This was evidenced on several occasions as drivers on St James drove into traffic on Colborne as if they expected that the Colborne traffic was going to stop at the intersection. Similarly we observed several drivers on Colborne Street come to a stop at St James for no reason, as if they believed that there was a stop sign for their direction of travel. These unusual behaviours resulted in several close calls where collisions were barely avoided.
Evaluation of the Need For A Protected Cycling Lane
The results from Session #2 showed that 443 northbound motor vehicles were documented over a 2-hour period. Due to the extensive time commitment we determined it was not realistic to conduct the additional documentation of southbound traffic. It is possible to simply double the northbound observations and conclude (with some error) that the traffic volume was about 886 vehicles in two hours, or about 443 vehicles per hour. A common way of estimating AADT is to multiply the peak hour of traffic by 10. This method does not always provide a good estimate on some roadways. However if our results were multiplied by 10 then we would arrive at an estimated AADT of about 4430 vehicles. This is not far off from the AADT posted on the City of London map of traffic volumes for this location. So we could use this estimate in the graph shown in Book 18 of the Ontario Traffic Manual. That graph is copied below.
Next we need to consider the appropriate speed to use in the above graph. As seen in the above graph we have inserted the vertical line representing the estimated traffic volume. We have also inserted the box in red which matches operating speeds between 45 and 50 km/h. Although the graph advises using the posted speed of the road (which would be 40 km/h) footnote #1 indicates the following:
“Operating speeds are assumed to be similar to posted speeds. If evidence suggests this is not the case, practitioners may consider using 85th percentile speeds…”
Our observations indicate that vehicle speeds are higher than this posted speed. In Session #1 we determined that the 85th Percentile Speed was about 51-52 km/h even when “non-free-flow” vehicles are included. The identical analysis with the data from Session #2 revealed an 85th Percentile Speed between 49.0 and 49.3 km/h. So there is some reason to believe that the speed to be used in the above graph should be close to 50 km/h, or slightly greater.
Book 18 suggests that use of the graph is just a starting point for determining the correct cycling infrastructure. A list of heuristics, or rules, in further consideration of selecting appropriate cycling infrastructure is copied in the two charts below.
An issue noted at the Colborne Street site is the existence of a bus route while the City’s decision is to narrow the travel lanes to just 3.3 metres in width. A lane that is 3.3 metres wide is too narrow for typical bus or large truck travel when accompanied by unprotected cycling lanes.
The rules also fail to recognize the danger of the unsignalized intersection of Colborne Street at St James. This is a unique circumstance where drivers are confused about their right-of-way. Although no analysis has been conducted at this time our observations during the peaks hours between 1600 and 1800 hours indicate that there are many motor vehicles using the intersection both from Colborne and from St James.
Other matters need further study, such as the number of pedestrians using the area. Our observations suggest that the number of pedestrians is relatively high.
A third videotaping session was completed on October 5, 2022 however no analysis has been done at this time. There is considerable time required to conduct these analyses manually and without any voluntary help. Anyone wishing to volunteer to help with the analysis can contact Zyg Gorski at the e-mail address: [email protected].