Attached in this article are the tables of individual, road-segment, surface-condition data obtained by Gorski Consulting during testing on May 15, 2019.
The first table contains data for the eastbound Lincoln Alexander Parkway.
The next table contains data for the westbound Lincoln Alexander Parkway.
The next table contains data for the northbound Red Hill Valley Parkway.
The final table, below, contains data for the southbound Red Hill Valley Parkway.
Different colour coding has been traditionally used in the Gorski Consulting Road Data to provide a quick illumination of road differences. In all four tables the data in green indicate that the road segment produced a low level of lateral and longitudinal motion of the test vehicle, below 0.0200 radians per second. Values between 0.0200 and 0.0500 have traditionally be displayed in black to signify less than ideal conditions that would likely contain some local problem areas within the road segment. If a road segment contained an average motion that was over 0.0500 then it would be displayed in red. Such a condition would generally indicate that there are major problems in the condition of the surface through a large portion of the road segment .It can be noted that none of the averages of any of the road segments are displayed in red.
There are several cautions that need to be mentioned when interpreting this data. The obvious caution is that it only displays the condition of the road interacting with the test vehicle’s tires. Thus it does not provide an indication of what problems may exist in a particular lane that have not been contacted by the test vehicle. While this may be a shortcoming, it also reflects the important issue that we would want to know what portions of a road surface are relevant to the typical travel path of a vehicle. It is important to recognize that this data is obtained from the motion of a passenger car and the motions caused in other vehicles may be different. So the motions of a large bus, heavy truck or motorcycle may be influenced differently from the passenger car in this testing.
Also the average of the motions shown in the attached tables provide very little information about specfic, local portions of roadway that may contain very rough or very smooth areas. At highway speeds of 90 km/h a vehicle travels about 25 metres per second. In the 30-second segments of roadway this represents a distance of about 750 metres. Thus many areas within that distance could contain substantial differences in their character compared to the reported average. It is essential to examine the charts of the motions, which display data at about 30 samples per second, to detect if local problems exist in a particular road segment.
As an example, the chart below shows the specific data for the westbound segment of the Lincoln Alexander Parkway between Dartnall Rd and Upper Ottawa Street. The table of average motions (shown above) indated that the average motions for this road segment were as follows: Lateral Rotation = 0.0345, Longitudinal = 0.0144. Yet looking at the actual chart of individual motions some differences emerge.
What can be seen in the above chart is there appears to be large spike in the motion data approximately in the middle of the data. The data in the first half of the chart seems to show much less motion than the data following the noted spike.
When we look closer at the first half of the data, before the spike, we get the following averages: Lateral Rotation = 0.0231, Longitudinal Rotation = 0.0105. We can then compare this to the averages in the second half of the chart, after (and including) the spike: Lateral Rotation = 0.0427, Longitudinal Rotation = 0.0173.
We can even look closer at the narrow band of data for the half-second interval surrounding the spike and obtain the following motions: Lateral Rotation = 0.1187, Longitudinal Rotation = 0.0316.
So, clearly, what the data shows is that the westbound test vehicle moves from a length of roadway which is relatively smooth, as demonstrated in the first half of the data, then the vehicle experiences a major spike in its motion, followed by an increase in the vehicle’s motion through the remainder of the road segment. In our view, the spike may be the boundry line between the newer and smoother pavement of the Red Hill Valley and the older and rougher pavement of the Lincoln Alexander Parkway. One could explore this further by examining old photos of the Parkways and seeing where the paving began when the Red Hill Valley was being constructed. If the road segment was 750 metres long and if the spike occurred at approximately halfway, then the spike should be approximately 375 metres before reaching the Ottawa St overpass, as shown using the GoogleMaps measuring procedure below.
Since video cameras were also functioning while this data was being collected we would also be able to view those and determine precisely where this spike occurred. However we need not proceed to that detail given the illustrative nature of this exercise. Even if we are wrong in our interpretation, the point is that the methods shown here demonstrate how we can use the Gorski Consulting Road Data, video footage and other resources such as GoogleMaps to conduct detailed studies of roadways and their surfaces. The costs of conducting such activities are low in terms of the equipment needed. The major expense is in the time required to conduct the testing and, even more so, the time required to process the data. Yet it is rather non-invasive in that no traffic has been disturbed and most drivers would not even detect that road meaurements were being gathered except for the unusual number of video cameras mounted inside and outside of the test vehicle.
A recent complaint was sent to the Hamilton Spectator newspaper from an experienced bus/truck driving instructor who observed some unusual motions of his bus as it travelled through the newly-paved, northbound portion of the Red Hill Valley Parkway. Given the credentials of the complainant we thought it was worthwhile to return and conduct further testing to determine if the complainant’s comments were valid. As a result another testing session was conducted on June 16, 2019 along the northbound Red Hilll Valley Parkway and also along both directions of the Lincoln Alexander Parkway. Analysis of this additonal testing still needs to be commenced and it is likely to be time-consuming. However it may be worthwhile to examine the data on the Red Hill Valley Parkway before and after the re-paving of the surface. We hope readers stay tuned to obtain the data from that additional testing which will be posted on this Gorski Consulting website in the near future.
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