Calculation of traffic volumes have now been completed from the videotaping session on Wednesday, December 19, 2018. These calculations have been added to the table of the other sites and the new table is shown below.
The results show that the Wednesday videotaping session at Kenesserie Road resulted in heavy truck volume of almost 48%. This is consistent with the other weekday (Monday) session at Graham Road where the heavy truck percentage was 48.6%.
Two heavy truck collisions occurred this month with the recently-installed cable barrier. In both instances the cable barrier allowed the trucks to cross the median and enter into the opposing lanes of traffic. The photo below shows the cable barrier from an eastward view on the overpass at Kenesserie Road. It can be seen that the cable barrier exists only the the eastbound side of the median. Thus westbound vehicles are allowed to travel through the median and do not reach the barrier until they are only a couple of metres away from the eastbound lanes.
View looking eastward from the Kenesserie Road overpass on Highway 401. The new High Tension Cable Median Barrier is shown positioned along the north edge of the eastbound lanes. Videotaping was conducted of the westbound traffic.
Our experience from the 1980s has involved the detailed documentation of the travel paths of vehicles that passed through the median and were involved in median crossover collisions. The general public may not understand that, even though the median slope, width and surface are engineered to certain standards, the expectation that vehicles will travel through that median in a controlled and predictable manner is unreasonable. Our detailed measurements of the physical evidence along with our reconstruction of vehicle motions and paths has demonstrated that vehicle motion though such medians is chaotic and unpredictable. Thus impacts of the cable barrier on the far side of the median would also be expected to be chaotic and unpredictable. Since the heavy truck traffic volume on weekdays is likely to be approaching 50% of the total traffic many of these heavy trucks will travel through the median in an unpredictable trajectory and their manner of engagement with the cable barrier cannot be guaranteed.
It remains to be seen how the new cable barrier will perform as more impacts by heavy trucks are documented. However the crucial issue is that these incidents need to be properly and fully documented and that documentation needs to be made available to the general public who use this highway.
You must be logged in to post a comment.