This median cross-over collision occurred on Highway 401 at Merlin Road in December of 2018 even though a cable barrier was installed at the location.

While it is good news that the Ontario government announced the first phase of construction on a median barrier in Highway 401’s “Carnage Alley” the news may not be all good. The flip side of this news is that construction will mean additional deaths if the Province does not have a plan to deal with deadly construction traffic conflicts on this high speed highway. The goal is to complete this first phase of construction by the year 2022. It will involve an 11 kilometre segment from the Town of Tilbury to Merlin Road. Other phases will follow.┬áDuring these multiple years of construction closed lanes will mean that the normal flow of traffic will be disrupted and collisions will be caused. The Province of Ontario has never provided a public account of the number of collisions that occur as a result of such flow disruptions. This is not surprising as such information could cast focus on the government’s activities and whether reasonable precautions and plans were developed to minimize collisions. Also many news reports of collisions often hide the fact that a collision on Highway 401 was related to construction activity.

The building of a concrete barrier will also include the widening of Highway 401 to 3 lanes in each direction. This is also good and bad news. More lanes mean an easing of traffic congestion. However the existence of a third lane will mean that the large percentage of heavy truck traffic will be located predominantly in that far right lane. When an emergency occurs, and there is a loss-of-directional control, such a truck will very often be directed toward the concrete barrier. The problem is that, when such a truck is located far away from the barrier it has an opportunity to change its direction of travel more so than if it were located in the passing lane, close to the barrier. Thus the angle of approach to the barrier will be increased. It is the angle of approach that is an important factor in the severity of an impact with a barrier. When a heavily loaded truck strikes a concrete barrier at a sharp angle there is no guarantee that the barrier will remain intact or that the truck will be held back from plowing through or over it. The characteristics of the barrier are important to identify so that it can be judged whether it will meet the demands of a heavy truck impact.

In the U.S. new procedures for testing the safety of roadside hardware have been published in the “Manual for Assessing Safety Hardware” or MASH for short. Six different test levels are described and the higher test levels involve progressively larger vehicles. For example Test Levels 5 and 6 (TL-5 and TL-6) involve a tractor-trailer, weighing about 79,000 lbs, travelling at 50 mph and striking the barrier at an angle of 15 degrees. While this information is available to the U.S. public essentially no comparable information about testing procedures is publicly available in Ontario. Has Ontario adopted the MASH procedures for assessing the safety of the Highway 401 median barrier? Has the proposed barrier been tested under similar test levels? No one has asked these important questions.