8 Ball In The Wind

Friday, May 5, 2017

Washington State Can Help Reduce Motorcycle Fatalities

"Rumble strip usage on the shoulders of undivided highways demands strategic application because bicycle usage is more prevalent along the shoulders of these roadways.  Rumble strips affect the comfort and control of bicycle riders; consequently their use is to be limited to highway corridors that experience high levels of run-off-the-road accidents." Washington State Dept. Of Transportation Webpage on rumble strips.

Bicyclists only have to contend with rumble strips along the shoulders of highways.  Yet on an increasing number of highways motorcyclists are being forced to contend with rumble strips on both the center line and shoulder of highways.  Since it is known that rumble strips affect the "comfort and control" of bicycles that their use is limited, why is it that the concept of rumble strips affecting the "comfort and control" of motorcyclists is virtually disregarded?

It seems the "comfort and control" of bicyclists may be more important to highway engineers and designers than that of motorcyclists.  Are there other highway features that engineers and designers haven't taken motorcycles into consideration along the highway?

According to a 2016 Texas A&M report by Dr. Chiara Dobrovolny, Phd., there are "no US testing standards for motorcycle riders safety when impacting roadside safety devices".  Even though (according to Dr. Dobrovolny's report) "approximately 50% of motorcycle crashes into barriers occur with the rider in the upright position", there are no world testing standards when impacting in the upright position.  This may explain why automobile occupant deaths have declined significantly since 1975, while motorcycle fatalities have appeared to remain relatively unchanged, or possibly risen slightly.

In the 2005 German study by Berg, the following photos were taken during a test of the effects to a motorcyclist impacting a typical “W Beam” guardrail while upright.  During this test the dummy slides alongside and onto the steel guard rail. Here, the rider would have suffered severe injuries especially to the shoulder, the chest and the pelvis corresponding to aggressive contacts and snagging with some of the roadside protection system’s stiff parts and open profiles.

The Berg study also examined a motorcyclist collision with the guardrail when sliding into it after laying the motorcycle down.  The high impact loads of the impact with the sigma post were beyond the biomechanical limits for the head of the test dummy.  The motorcycle became stuck beneath the rail, and the rider struck with extreme, and most likely fatal force. This was from an impact test speed of only 37 mph.   

Even the ubiquitous “Jersey Barrier” can pose a serious threat as shown by the Berg study.  Since when striking the barrier upright,
the motorcycle and rider do not decelerate quickly, there is a higher risk of the rider being thrown into oncoming traffic than with the metal barrier.  Also, the concrete is not flexible and therefore does not dissipate the impact force as well as the steel barrier does. 

When the motorcycle collision occurred while sliding into the concrete barrier the risk of injury was much higher due to impact loads.  As this excerpt from the Berg study demonstrates; "Deceleration of the motorcycle and dummy were not as rapid as during the impact where the motorcycle slid into the guard rail made from steel.  Nevertheless the measures dummy deceleration for the primary impact were high, indicating a risk of severe and life-threatening injuries.  The dummy head loads again lay clearly above the biomechanical limits."  Clearly colliding with the "safety barrier" while sliding adds a significant risk of "severe and life-threatening" injuries during a collision.

While their isn't a great deal of options for mitigating the danger of colliding with the concrete 'Jersey Barrier", there are options for mitigating the risk of injuries to motorcyclists from the steel barriers that are even more common place than the concrete ones.  Proven effective in use in countries around the world, these solutions for mitigating the risk of severe  or life-threatening injuries for motorcyclists in a crash.

Numerous studies done around the world point to the effectiveness of several designs to prevent sliding motorcyclists from impacting the posts supporting the guard rail.  The extreme force of impacting a post while sliding can cause severe and even fatal injuries in a collision that otherwise could have been survivable with limited injuries.  Even the risk of injury from impacting the upper rail and sliding along it can be mitigated with existing technology.

If Washington State is serious about reaching its safety goal as set forth in its Strategic Highway Safety Plan (better known as ‘Target Zero’) it will have to seriously look at mitigating the dangers of its highway features.  Features that may be perfectly safe and beneficial to the safety of larger motor vehicles, can have unintended and dangerously affect the "control and comfort" of a motorcyclist.  Depending on the skill level of the rider, this sudden loss of stability and control of the motorcycle can be a major factor leading to a single vehicle crash.  While safety training and rider education and public awareness of motorcycles are all good strategies to take in pursuit of achieving even a significant reduction in motorcycle fatalities, mitigating the dangers of roadway "safety" features can be a tangible and effective measure to take towards attaining the Strategic Highway Safety Plan's goals.  Which we motorcyclists are truly concerned about.  After all, it is our lives that are involved in this ongoing discussion on 'motorcycle safety'.  

If the state considers the "comfort and control" of bicyclists when building and maintaining highway safety features, it should at least place as much consideration on motorcyclist safety.  

Catch you on the road sometime...

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