Those who understand road safety issues can focus the public’s attention to issues that may not be readily apparent. That was the case in the latest, multi-fatal, double-decker bus crash in Hong Kong yesterday that killed 6 passengers.
It did not take long for Professor Ahmed Shalaby, a road safety expert and Professor in the Civil Engineering Department at the University of Manitoba, to post the following on his twitter account:
“A Hong Kong double-decker bus collided with a roadside barrier and then a tree immediately behind it. In addition to speeding, two other factors increased the severity of crash. Lack of crashworthiness standards for buses, and roadside barriers that don’t shield large vehicles.”
In these few words he encapsulated the major problems that were not mentioned in numerous news media posts.
In Professor Shalaby’s last sentence “…roadside barriers that don’t shield large vehicles” he pointed out that the highway at the Hong Kong site contained a barrier that was the initial point of contact. Although no views of that barrier have been shown at that specific point of contact, its characteristics can be seen in the photo below, where the damaged bus is stopped next to the barrier.
Clearly, compared to the height of the bus, the barrier is very low. The barrier could not possibly stop the bus from tipping, or tripping over it, thus exposing the upper deck of the bus to a tree impact. The tree itself was likely much too close to the busy highway. The large orange circle in the above photo shows the evidence where the left-front corner of the bus likely struck the barrier and then the bus was rotated over top of the barrier.
Professor Shalaby was also right in confirming that speed might have been a factor in the crash but he also highlighted the issue of “Lack of crashworthiness”: the degree to which the design of the structure of the bus reduces the probability of injury and death to its occupants. Such crashworthiness has been enshrined in passenger vehicle and light truck safety standards since the 1960s. Yet, crash after crash demonstrates that there is almost no safety design in the structure of large, intercity coaches, worldwide.
That lack of bus structure crashworthiness becomes obvious when examining the above photo and considering the characteristics of the damage where the upper deck of the bus became opened up like someone used a can opener to cut off its lid. The important evidence is that the tearing and rupturing of the sheet metal is not accompanied by any buckling or crush of the structure next to it. When a structure is strong or stiff it will buckle and crush before it finally ruptures and separates. Because the surrounding structure near the tears and ruptures is almost undamaged it is an indicator of the weakness of that structure – the fact that it separated without much force being applied to cause that separation. This occurrence is reminiscent of a similar occurrence in a multi-fatal bus crash with a train near Ottawa in 2013 where the bus structure was separated with minimal evidence of any disruption in the vicinity of the separation.
Professor Shalaby has been raising this issue of lack of bus crashworthiness through mediums such as the Canadian Parliamentary Committee on Bus Passenger Safety this past spring. His report (co-authored by Zygmunt M. Gorski) highlighted this issue of lack of bus structural crashworthiness. Unfortunately, the Canadian federal election caused a disbanding of the Parliamentary Committee and therefore there has been a delay in the Federal government’s action on this important issue.
We must understand that collisions such as the one in Hong Kong are not that different from what could occur in Canada. The same lack of compatibility of the roadway infrastructure and poor bus crashworthiness exists here and will likely rear its ugly head in the next, multi-fatal, bus crash much like the one involving the Humboldt Broncos collision in Saskatchewan in April, 2018. These may be difficult issues with costly price tags. But they need to be discussed with the Canadian federal government joining the Provinces in a joint strategy along with the U.S. National Highway Traffic Safety Administration (NHTSA), Federal Highway Administration (FHWA), U.S. States, bus manufacturers and all other interested parties. A change must occur because there is a dire need for that change.