Background
Recently Gorski Consulting has been involved in a study of speeding and the functioning of a Speed Display Board (SDB) erected on Hale Street in London, Ontario, Canada. Preliminary results of the study were posted on October 11, 2024, in a Gorski Consulting website article entitled “Motor Vehicle Speed Detection in London, Ontario, Canada”. That article discussed the analysis of a two-hour video session conducted on October 5, 2024 between 2050 and 2250 hours. Since then additional video sessions were completed and analysed comprising of 8, 2-hour sessions. The present article will review the results from 7 of these sessions. The dates and times of the 8 sessions are noted below.
October 4, 2024 between 2100 & 2300 hours
October 5, 2024 between 0600 & 0800 hours
October 5, 2024 between 1600 & 1800 hours
October 5, 2024 between 2050 & 2250 hours
October 14, 2024, between 1500 & 1700 hours
October 15, 2024, between 1700 & 1900 hours
October 21, 2024 between 1800 & 2000 hours
October 30, 2024, between 1000 & 1150 hours.
There was a technical problem with a portion of video from one of the cameras in the October 4, 2024 session that prevented last hour of the session from being analysed. Thus the first hour of that session could still be analysed but this has not been done. For the present article only the results from the last 7 sessions will be reviewed.
The table below shows these results.
The SDB was removed on November 4, 2024 or exactly one month after it was erected. Looking at the results in the table there is no indication that the speeds of vehicles were lowed by the presence of the SDB. The average maximum speeds were substantially higher than the Posted Maximum Speed for the road. Also of concern is the high percentage of vehicles found to be travelling at 20 or more kilometres above the posted speed limit.
Because of the erratic functioning of the SDB only a small segment of the northbound vehicles could be included in this documentation. The SDB was confused whenever two or more vehicles existed in the 180-metre detection zone. So the only observations that could be included were those where there was only one vehicle present in that zone. On a number of occasions, even when a single vehicle was present in that zone, the SDB would, inexplicable, fail to detect the presence of the vehicle.
In other instances the SDB would continue displaying a speed well after the observed vehicle had exited the detection zone. In those instances when a second vehicle entered the detection zone the speed from the exited vehicle continued to be displayed and so the data from the second observation had to be aborted because it could not be certain whether the SDB was still showing the speed from the first vehicle or whether it was now showing the speed from the vehicle that entered the detection zone.
In conditions where it was sunny, or partially sunny, the SDB had difficulty detecting a vehicle in the detection zone, even when only one vehicle existed. Thus many observations in those conditions had to be aborted.
In many instances the SDB was late in detecting a vehicle until it was almost leaving the detection zone. It was not clear why this occurred. This often occurred in daylight hours. Yet upon approaching darkness, or in nighttime conditions, the SDB was often able to detect vehicles close to the start of the 180-metre detection zone. Our decision was to include those vehicles in our analysis even though the SDB was late in detecting them, so long as only one vehicle was present in the detection zone and there was no ambiguity as to the vehicle speed being reported by the SDB.
Despite these difficulties previous testing has shown that SDBs were reasonably accurate in displaying speed. This was confirmed on previous occasions by our multi-video camera testing where we could independently compare the SDB’s display to the speed that was calculated from our synchronized video-camera test methods.
So the primary problem is that the results from the SDB would not be reliable if an analyst was attempting to determine the average speed of all vehicles passing through the site. Because of the problems that the SDB had in detecting every vehicle such an analysis would not be possible. It is not known at this time whether the SDBs erected on Hale Street had the capability of recording events and creating a file of all the displays from the SDB. This could be a concern if officials from a municipality were to use such data blindly without knowing that the file would be greatly corrupted by the discussed detection problems.
It is reasonable however, from our experience in assessing the SDB’s functioning, that accurate speed data can be selected from the display by watching its function through video while also watching a vehicle passing through the detection zone, and then selecting those observations where the displayed speed was known to be accurate.
The observations shown in the above table are only those where a driver was not interfered with selecting a speed of their own free will. Thus they were not obstructed by vehicles ahead of them and their reported speed was not corrupted by any other vehicles with the SDBs detection zone. Thus these observations are an accurate reflection of what speeds drivers selected even though a Maximum Posted Speed sign was located, and clearly visible, just beyond 100 metres south of the start of the detection zone. It was noted that of the total of 719 observations there were only 4 in which a vehicle’s maximum speed was 40 km/h or lower. This is only about 0.56%. So one could argue that about 99.5% of northbound drivers on Hale Street were speeding because they were travelling above the posted speed limit. The Maximum Posted Speed sign had been erected in September 2022 or over two years prior to this study.
Discussion
When a maximum posted speed of 5 km/h is posted on any roadway it is highly likely that all motor vehicles travelling through it will be ‘speeding’. But is that a fault of the drivers or is it the fault of posting an unreasonably low maximum speed? Any reasonable person would conclude that the 5 km/h posted speed was unreasonable. So an important component of the issue is whether a posted speed limit is reasonable. Reductions in motor vehicle speed provide obvious benefits. Vehicles travelling at slower speeds are likely to improve traffic safety. But a negative aspect is that they also increase the time required for persons to reach their destinations. These two conflicting issues need to be kept in mind when considering what speed should be legal on any roadway.
Another short-sighted viewpoint expressed by many is that the posting of a lower speed limit will automatically reduce vehicle speeds. This study on Hale Street demonstrates the fallacy of such a belief since the speed limit was reduced over two years before this study yet the observed speeds are elevated.
Even when roadways are designed with speed-limiting features, they may not improve the overall benefit to society. Speed humps, in-lane obstructions and narrowed lanes are believed to improve safety by reducing vehicle speeds. But much of the research does not take into account the complicated factors that are neglected. While average speeds may be reduced there is little information whether the behavior of the small percentage of high-risk drivers is modified. In fact, the reduction of speed by the vast majority of drivers may simply hide the existence of the small percentage of high-risk drivers who continue to drive recklessly.
Also, many ‘minor’ collisions that are caused by speed-limiting features are hidden from official statistics. When a vehicle strikes a hazard marker placed within a lane there could be relatively minor damage but the reality is that it is costly. A vehicle must be taken into an autobody shop to make those repairs. And the owner loses time which is also a cost that is not taken into account. And when such a roadway obstacle is struck it may also sustain damage that needs to be repaired. A roadway repair crew must come to the site and do the repairs but often that cost is not taken into account. Vehicles are also damaged by striking the curb of a narrowed roadway. And collisions can occur when drivers travel too quickly over a speed hump. All these instances are not taken into account yet they are factors in the cost-benefit analysis to society as a whole.
Yet there is reason to be concerned about the elevated, observed speeds on Hale Street. Our estimate indicates that Hale Street has a width of about 11.4 metres. When we consider that most lanes on collector roads would be about 3.5 metres wide, then a typical street would be about 7.0 in width. The additional 4.4 metres of width on Hale Street means that those attempting to cross it will experience some challenges when motor vehicle speeds are high. It is also likely that vulnerable persons might be in danger. Pedestrians crossing Hale Street may have difficulties so there has to be some research done to determine how many pedestrians exist in the area, how many of them cross Hale Street and whether their characteristics (age, frailty) might need additional attention. There is a transit bus route on Hale Street which might also attract pedestrians. And the volume of cyclists using Hale Street must also be taken into considerable.
In all this study has demonstrated some challenges on many fronts. However it also provides some useful data about the existence of motor vehicle speeding in London and how the functioning of Speed Display Boards may need a second look.
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