Drivers Beware – Road Data Shows Important Differences in 400 Series Highways in Southwestern Ontario
Drivers in Ontario have an objective way of comparing the safety of road surfaces. In the most recent series of testing, Gorski Consulting has compared the surfaces of Highway 401 and 402 with interesting, and differing, results.
The testing involved driving a test vehicle along each highway and documenting the amount of disturbance of the vehicle motion. The “Lateral Rotation” or sideways motion, and “Longitudinal Rotation”, or forward/back motion were sensed. This data was collected at 30 second intervals or, at highway speed (110 km/h), for approximately 900-metre distances. The averages of these motions were obtained and these will be reported.
It had been previously noted that vehicle motions under 0.0200 radians per second indicate a good surface, values between 0.0200 and 0.0500 indicate varying degrees of danger that could be hiding a local safety problem, and values above 0.0500 indicate that major road surface problems likely exist throughout the tested road segment. However there are other, complicating factors. When road surfaces become slippery due to rain, snow or ice there are greater chances of causing loss-of-control because of the lower tire force. There are also issues of speed of a vehicle and the traffic volume. Thus motions caused to a vehicle travelling at high speed are of greater concern even though the distrubed motion is lower. Similarly roads that have high traffic volumes have a greater chance of causing loss-of-control incidents simply because there are more opportunities available. The results of pervious testing have been uploaded to the Road Data page of the Gorski Consulting website.
The results of the most recent testing on Highways 401 and 402 are summarized here in a set of three charts, shown below. The first chart shows the data travelling westbound on Highway 401 from London to Tilbury. The second chart shows the data travelling eastbound on Highway 402 from Strathroy to London. The third chart shows the data from travelling westbound from London to Strathroy. Discontinuities in the Highway 401 data are because not all the collected data was analysed because there was too much data and it would be too time-consuming to analyse it all; thus various areas of the highway are shown in the chart.
Even without discussing the details of the charts, a simple, visual, comparison of the magnitude of the peaks in the data should demonstrate the large differences in the road segments.
The differences can be noted in numeric form by summarizing the lateral and longitudinal data for all the road segments on each highway as shown below.
The data for westbound Highway 401 indicates a suface that is generally in good condition although we previously reported that local problems exist. In an earlier article we used the example of a large disturbance in motion that occurred near the Merllin Road overpass, west of Chatham, Ontario.
The data for eastbound Hwy 402 show elevated values of lateral rotation. In particular the segment between 1.425 and 2.342 kilometres east of the Scotchmere Drive overpass provided readings of: Lateral Rotation = 0.0239, Longitudinal Rotation = 0.0156. While these values may not be alarming for low-speed, low-volume roads, their existence on this high-speed expressway should necessitate explanations.
However the real problems become apparent when examining the data for westbound travel on Highway 402. In three of the road segments the lateral rotation rose above 0.0300. Specifically, at the road segment approaching the Olde Drive overpass and for approximately 674 metres west of that overpass, the average lateral rotation was 0.0446. Again, this is a value that should be of some concern because it was obtained on a high-speed expressway rather than just on a low-speed urban road.
The three figures below show the condition of the westbound lanes of if Highway 402 on approach to the Olde Drive overpass as well as justs past it. These photos were taken on May 21, 2019. Clearly the lanes are visibly in poor condition.
Westbound lanes of Highway 402 on approach to the Olde Drive overpass.
Westbound lanes of Highway 402 on approach to the Olde Driver overpass.
Westbound lanes of Highway 402 just past the Olde Drive overpass.
While some patching has been conducted there are dangerous areas of missing asphalt located along the lane-dividing line which would cause problems when drivers attempt to change lanes. The collected data does not demonstrate this danger because the test vehicle did not conduct lane changes at the time of the testing.
In comparison, the photo below shows an example of the type of surface that produced low levels of test-vehicle disturbance. This photo shows the eastbound lanes of Highway 402 just east of Centre Road where the surface has been freshly re-paved. This segment of highway produced the following data: Lateral Rotation = 0.0109, Longitudinal Rotation = 0067. This is not surprizing and it demonstrates the validity of the testing methods.
View of new asphalt on eastbound Highway 402 just east of Centre Road near Strathroy, Ontario.
The travelling public is kept unaware of these important differences in road surface conditons. When a vehicle loss-of-control occurs resulting in a collision there is no mention by police or the official news media about the conditions of the road surface and if it played a role in the incident. An important fact is the police are not experienced in recognizing dangerous road surfaces nor do they have any training or equipment to measure the extent of road surface problems. These facts result in the existence of dangerous conditions that are not recognized and continue to pose hidden safety problems to the travelling public.
Gorski & Shalaby Collaborate on Brief to Canadian Parliament’s Bus Passenger Safety Committee Meeting
It was a considerable honour to work with Professor Ahmed Shalaby, Professor, Department of Civil Engineering, Univ. of Manitoba, in preparing a co-authored brief that was presented to the House of Commons Committee on Transport, Infrastructure and Communities on the issue of Bus Passenger Safety. Our report, dated May 16, 2019 was uploaded to the committee site at the following address:
Click to access GorskiZygmunt-e.pdf
This 2013 crash of a bus with a train outside Ottawa demonstrated the need for improvements in bus structure crashworthiness.
High-lights from the brief included a discussion of the incompatibility of full size buses with impacts to roadside structures that are primarily designed for impact by passenger cars and light trucks. Photos of some exemplar collisions from other countries helped to illustrate that our roadsides and buses are fundamentally similar and instances of multiple fatalities can be used as warnings of potentially similar tragic consequences in Canada.
The view was expressed that, while seat-belts should be installed in inter-city coaches that travel at highway speeds, the scenario is not the same for school buses where there is a real danger of causing major injuries and deaths to children from usage of improper restraints as well of improper usage of proper restraints. It was emphasized that abdominal injury to children is a real danger when the lap portion of a seat-belt restraint is not properly positioned/adjusted and in some instances proper positioning/adjustment cannot occur due to the usage of restraints that are inappropriate for the size of the child.
A recommendation called for a federal agency such as the Transportation Safety Board (TSB) to become empowered to investigate motor vehicle collisions in a similar capacity to the U.S. National Transportation Safety Board (NTSB). Up to now the TSB is not mandated to examine motor vehicle collisions unless they involve an impact of a vehicle from another mode of transportation such as an airliner or railway train.
How many times has a school bus been struck by an airplane? Yet this is the kind of collision that the Canadian Transportation Safety Board is mandated to examine.
The problem was glaring in wake of the tragic Humboldt Broncos bus crash in Saskatchewan over a year ago. No independent safety agency was mandated to conduct that investigation causing the RCMP, who are paid by the Province of Saskatchewan, not to release their report of the incident. One of the major causes of the crash, the blockage of sight lines at the intersection, was never properly revealed to the general public. Additional details about further causes, and how the bus passengers sustained their injuries were also never revealed. Such basic inadequacies would be expected to be nullified if a purely independent agency such as the TSB was involved in the investigation.
Recent, multiple-fatality, collisions of buses in the Ottawa area involving a train and the impact of a double-decker with an overhanging structure at a bus station were also emphasized for the inadequacy of crashworthiness of bus structures.
The need for more detailed, reliable and publicly available collision data was also recommended. The current National Collision Database organized by Transport Canada from Provincial crash data needs improvements and the U.S. Fatality Analysis Reporting System (FARS) was referenced as the type of system that may be appropriate.
In summary, while bus transportation of passengers remains safe, it only requires a single major incident to cause multiple fatalities. Continued threats such as incompatible roadside structures, poor crashworthiness, entrapment during incidents of fire and drowning, along with a lack in proper documentation of these incidents continue to await improvements and leadership from the Canadian federal government.
Some Collision Scenarios Are Challenging
There are some collisions scenarios where seat-belts, air bags and crumple zones will not help, but there are still escape routes!
This is an extreme example of “roof structural intrusion” that challenges vehicle safety design engineers.
The above photo demonstrates that, despite the propaganda, there are limits to what vehicle safety design engineers can accomplish to keep you safe. A collision like this is often caused by striking the side of a box-type, semi-trailer at high speed. Death can sometimes be escaped if you duck down because the severity of the impact is much less than it might seem. The upper structures of a car are soft, meaning that they become crushed and displaced at much lower forces than if the contact was made to the bumper level. So in this scenario, it is not so much that the change-in-velocity (Delta-V) is the killer, but more so that the structure of the vehicle has come into the occupant space. Seat-belts and air bags are of limited or of no benefit in this scenario. Fortunately these happenings are very rare.
Where scenarios like these occur, escape is still possible through new technology such as Automatic Emergency Braking (AEB). Thus sensors might detect the present of a tractor-trailer that is backing into a driveway and is straddling the lane in which you are approaching. You may not detect the trailer at night or in poor weather conditions but the sensor technology can. Brakes can be applied automatically without your approval, most likely resulting in your survival. AEB is perhaps the most beneficial safety device that has come along since seat-belts. Now we just have to make sure they function reliably in a very high percentage of all collision scenarios where they are needed.
Highway 401 Road Surface Is Not Without Local Safety Problems
While testing by Gorski Consulting showed that the westbound Highway 401 between London and Tilbury was generally in good condition, local safety problems were also noted. This is a problem when drivers expecting a good, smooth surface are suddenly faced with a local disruption which could cause a vehicle loss of control.
An example of these local variations in the road surface can been observed in a “spot” deficiency in the vicinity of 1 to 2 kilometres west of Merlin Road, a location that is just west of Chatham, Ontario. The four figures below, taken from Google Maps, show the specific location on Highway 401 where the road surface problem was detected.
Area of Merlin Road located south-west of Chatham, Ontario.
Specific location of Merlin Road along Highway 401 where a road surface problem was detected.
Overhead, Google Maps, view of the location along westbound Highway 401 where a road surface problem was detected.
This westbound view, from Google Maps, along Highway 401 shows the area of a small bridge crossing a drain where there was a disruption noted in the test vehicle’s motion.
The following views are taken from our video-editting program showing synchronized camera views as our test vehicle approached the noted bridge.
View, looking westbound on Highway 401 as our test vehicle approaches the area of the small bridge.
View approaching the small bridge.
View approaching the small bridge.
The figure below shows our test data taken on May 5, 2019, over a time of 30 seconds, travelling at approximately 111 km/h in the vicinity of 1 to 2 kilometres west of Merlin Road. The data at the extreme right end of the chart, emphasized by the large green oval, shows the area where our test vehicle passed over the noted bridge.
The green oval in this chart shows the area where the test vehicle crossed over the small bridge.
Selecting 12 samples of data taken around this upheaval it was noted that the standard deviation in the test vehicle’s lateral rotation was 0.0678 radians per second. This is much greater than the average lateral rotation over the full 30 seconds which was 0.0185 radians per second. It can be recalled that our sampling rate while conducting the testing was at 30 per second. So the 12 samples would represent a time just less than a half second. While this is a relatively small time it is more than sufficient to cause a notable disruption in the test vehicle’s motion.
Obviously there is little problem with this occurrence when the road surface is dry and bare. However that will not always be the case. There will be occasions when vehicles may travel on a wet surface, or even in snow or ice. In those special conditions of ice and snow the tire force will drop dramatically. As a result disturbances in a vehicle’s motion during such conditions of low tire force can create a scenario where demand approaches the threshold of the available tire force. Especially in those conditions where a longitudinal rotation may result in the lifting of the vehicle’s mass, and thus reducing the tire force, precisely at the same time as a lateral rotation is initiated. When traffic volumes may be well over 20,000 units per day the potential for a least one vehicle experiencing a stability problem per day in winter conditions is not an alarmist’s expectation.
When such problems occur it is extremely rare that they are detected. A loss of control of one vehicle may result in many instances where the vehicle simply moves into another lane or onto a shoulder without any damage or apparent consequence to that vehicle. Yet encroachments into an adjacent lane can cause reactions by nearby, unsuspecting drivers who may react unpredictably, especially if they are caught off guard. A loss-of-control may then be initiated in the nearby vehicle potentially resulting in a collision. The relevance of the road surface disturbance would rarely be detected and even more rarely would it be noted as a cause in any official collision reporting. Investigating police have no objective methods or equipment to document the severity of road surface problems other than riding over them with a police vehicle and noting that a disturbance in motion is caused. Such subjective observations by investigators who have minimal or no experience or training in the comparison of road surface problems cannot result in any useful detection of those problems.
In summary, while we have reported favourable results in our earlier discussions of the quality of the road surface along Highway 401 it needs to be emphasized that the data displayed in the Road Data webpage of this Gorski Consulting website is in terms of averages over longer distances and times. Although the results from “spot” problems can be extracted, like shown above, those spot problems are too numerous to show in a data file that must show results over long lengths of many roads and highways.
Additional Road Data From Westbound Highway 401 Testing
What road surface conditions could make our vehicle go out of control and kill us? That should be an important issue to anyone who travels on any roadway.
Gorski Consulting has been gathering data on this issue for the past 5 years and this has been posted on the Road Data page of this Gorski Consulting website.
How much a test vehicle is “rocked” forward and back or sideways while travelling on a roadway is the data that is collected. The motion of the test vehicle is captured using an iPhone app. Also, multiple, video cameras are used to document the inside and outside of the vehicle along with views of the roadway. The figure below shows an example of the views from 5 video cameras that were used while the road data was being captured in testing on May 5, 2019. This figure shows the area of westbound Highway 401 approaching Union Road.
A screenshot taken from our video-editing program showing 5 camera views that were used during our creation of the road data of May 5, 2019.
The above figure shows the situation on Highway 401 near Union Road where the road surface had been laid in concrete in the summer of 2018. The area is still a construction zone as can be noted by the portable concrete barrier along the median.
On May 24, 2019 a small portion of the latest data was uploaded in an article on this website. Subsequently we have been busy analysing more data such that we now have a substantial portion of the westbound Highway 401 documented from London to Tilbury, Ontario. The updated table is now too large to display as a figure in this article however it will be added to the Road Data page of this website.
Although the general focus of the testing was to obtain motion data of the test vehicle that could be compared to the previous testing, we were particularly interested in studying the difference between the new concrete surface of Highway 401 versus the older asphalt surface. We wanted to know if there was any difference in the motion of the test vehicle as it rode over these two surfaces. As may be recalled, the motion data that is captured is the “longitudinal rotation” and the “lateral rotation” of the vehicle. This longitudinal rotation is what would happen if one were to stand at the front of a car, place one’s hands on the front of hood, and press down to cause a rocking of the vehicle, up and down, alternating, at the front and rear of the vehicle. Lateral rotation is what would happen if one stood at the side of the car’s roof and began pushing sideways thus causing the vehicle to rock back and forth sideways.
The motion of the vehicle is documented in terms of radians per second. One radian is equal to 57.3 degrees. From previous testing we had observed that a good quality road would cause rotations up to 0.0200 radians. A moderate quality road that contains some deficiencies would cause rotations between 0.0200 and 0.0500 radians and a poor quality road with significant safety issues would cause rotations above 0.0500 radians.
All the data in the westbound Highway 401 testing of May 5, 2019 produced motion values well below 0.0200 radians indicating that the road surface was in very good condition. This would be expected since Highway 401 carries the largest volume of traffic travelling at the highest speed and it would be expected to have the highest level of service. Yet there were some interesting findings.
Overall, for the full length of Highway 401 where data has been analysed, the average values were: Lateral Rotation = 0.0126, Longitudinal Rotation = 0.0096 radians.
We then looked at four segments of the highway according to whether the surface was asphalt or concrete and the differences are shown below.
In the article of May 24, 2019 we commented that the concrete surface appeared to produce more longitudinal rotation and less lateral rotation. Now that additional data has been obtained this relationship does not appear to hold. What was obvious, as previously noted, was the the speed of the test vehicle affected the results. So for the concrete surface commencing from Southminster Bourne Rd, the test vehicle was travelling in the range of 84 to 104 km/h because it was travelling in a construction zone. This was significantly slower than the 110 km/h speed that was used when travelling on the asphalt surface where there was no construction zone.
It became obvious that the concrete surface could produce substantial lateral rotation once the test vehicle approached the area of Tilbury, Ontario where there was no longer a construction zone and the speed of the test vehicle was increased to 111 km/h. At that point the lateral rotation values increased to an average of 0.0147 radians. While these data are interesting, overall they are all well below the 0.0200 threshold and we would classify this motion as quite low, indicating a good quality road surface.
As we stated before, these results may appear mundane. However they are important in terms of comparing the other roadways where testing was completed and the motions of the test vehicle were much more violent. Thus this data on Highway 401 presents a benchmark, an example of what motion values should be expected on a good quality road surface. It demonstrates that, if required, it is possible to construct any roadway with this level of quality. When other roadways fall short in their performance one can question why that had to be so and whether improvements are warranted.
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