Preliminary results are available from road surface testing of westbound Highway 401 conducted on May 5, 2019. The full testing commenced at Wonderland Road to Tilbury, Ontario and then the test vehicle turned around and continued from Tilbury back to Highbury Ave in London. The preliminary results shown here are for the short distance at the start of the testing from Wonderland Road to just past Mill Road, or a distance of just over 12 kilometres. This section of highway contained a relatively good asphalt surface from Wonderland to Southminster Bourne Road. At Southminster Bourne Road the surface changed to a new, concrete surface that had been laid in the summer of 2018. Thus it is possible compare the older asphalt surface to the new concrete surface. The preliminary data are shown below.
The above table also contains a small amount of data (at the top) from testing conducted in February, 2014 and June, 2018. When this table is completed it will display results from all testing conducted on 400-series highways in Ontario. A website article posted a couple of days ago described some of the additional results that will be added as analysis continues.
It can be recalled from previous articles posted on the Gorski Consulting website, a Road Data webpage on this site contains all the road data that has been collected since 2014. That data is divided into separate counties as well as the City of London.
The data describes how the motion of the test vehicle is affected by its travel over a road surface. This motion is described in terms of the vehicle’s rotation, both longitudinally and laterally. Some of the vehicle motion will be suppressed by the vehicle’s tires and suspension. What remains is the motion of the sprung mass, or that portion of the vehicle that is suspended on the unsprung wheels and suspension. Thus, after the vehicle’s suspension and tires have done their job to steady the vehicle, the remaining motion is what is being documented in our data. By using the same vehicle (2007 Buick Allure) in all the testing the variability caused by vehicle differences is removed.
From previous testing it was noted that a “good” road surface would create rotation rates between 0.0100 and 0.0200 radians per second. A road with some imperfections and comfort issues would contain values between 0.0200 and 0.0500 radians per second. A road with major road surface problems would contain rotation rates above 0.0500 radians per second.
So, looking at the present table, all the data are displayed in a green colour meaning that the values are all below 0.0200 and therefore the test vehicle sustained very little disturbance either in the “forward/backward” direction (longitudinal rotation) or in the “side to side” direction (lateral rotation). This would be generally expected for a 400-series highway where the highest level of service would be expected.
We were interested in the fact that the Ontario Ministry of Transportation has been laying a concrete surface along Highway 401 for several years now. It began when three lanes of travel were created just east of Windsor. This has progressed as reconstruction has been carried out toward London. While driving along this concrete surface it was noted that it was etched with longitudinal, likely for drainage, and that the louder sound and a sense of a higher vibration, were evident compared to the asphalt paving. Thus we were interested in comparing that concrete surface to the asphalt. As can be seen in the above table we now have some preliminary data that compares the two surfaces.
First of all, at the bottom of the table we can see the overall averages for the surfaces of Highway 401 is: Lateral = 0.0119 and Longitudinal = 0.0102. Separating the concrete from the asphalt we note the following averages:
Asphalt – Lateral = 0.0134, Longitudinal = 0.0098
Concrete – Lateral = 0.0113, Longitudinal = 0.0111
While this data is very limited it indicates what we expected. The concrete created a little more longitudinal rotation of the test vehicle in comparison to the asphalt. It also shows that the concrete surface produced slightly less lateral rotation that the asphalt.
While this data may not appear earth-shattering, it provides further information for comparison of various road surface conditions. As the Road Data database is expanded it will become more useful in its ability to compare various road surfaces in an objective manner. This data is completely independent of any influences or testing that has been performed by those agencies that construct and maintain the roads and highways in Ontario.