Injury Risk Curves for Motorcyclists
Motorcyclist injuries and fatalities are a world-wide concern. About 28% of 1.35 million annual road traffic fatalities are motorcyclists. In a collaboration between Autoliv and the Swedish Transport Administration, we investigated and modelled mathematically how the injury risk of motorcyclists in a road traffic crash is dependent on crash speeds and type of impacted objects.
The study was based on the German In-Depth Accident Study (GIDAS) data and published in Accident Analysis & Prevention (doi.org/10.1016/j.aap.2018.12.010). Free access until February 15th, 2019.
Not surprisingly, relative speed has a strong impact on the injury outcome: At 70 km/h, the risk for serious or fatal injuries in collisions with wide objects was 20%, with crash barriers 51% and with narrow objects 64%. Furthermore, head-on collisions between motorcycles and passenger cars, with both vehicles traveling at 60 km/h (a relative speed at 120 km/h), result in 55% risk of at least serious injury to the motorcyclist.
What do the findings imply? “According to the Safe System approach, speed limit compliance and crash protection are closely connected”, says Dr Matteo Rizzi, Road Safety Analyst at the Swedish Transport Administration.
The Safe System approach recognizes that humans make mistakes and have limits to withstand impact forces. Hence, the road transport system shall be designed to guide road users to a safe behaviour and to mitigate consequences of common human errors. Coming back to the motorcyclists, this means that we need to assume that motorcyclists will crash and we know that the impact forces will increase with speed. We need to ensure appropriate combinations of speed and protection so that the limits of the riders to withstand impact forces are not exceeded and injuries are avoided.
Dr Rizzi gives the example of a head-on collision between a helmeted motorcyclist at 60 km/h and another vehicle at the same speed which, according to the study, leads to a 55% risk of serious injury. “Taking this to rural roads where speeds can be even higher, today’s speed limits exceed the in-crash protection offered by motorcycles and protective gear to guarantee low injury risks. In other words, with today’s infrastructure and motorcycle design, the maximum speed limit should be below 60 km/h to reliably protect motorcyclists from serious injuries” he continues, well knowing that such an intervention is neither practically nor on the agenda. “This is probably not acceptable for most road users. Therefore, we need to develop integrated rider protection systems so that speed limits with higher user acceptability can be set.”
One way to tolerate current speed limits would be to improve motorcycle crashworthiness and link that to the infrastructure. Another way would be to develop systems that can reliably reduce speed prior to a collision (such as Autonomous Emergency Braking). With those measures, the set speed limits could be as high as today or even higher without necessarily imposing unacceptable injury risks.
The study will be a cornerstone towards making protection levels offered by pre-crash and in-crash protection comparable. Drawing on Autoliv’s experience of protecting pedestrians and bicyclists, the best solution is likely offered by combinations of pre-crash and in-crash protection. At Autoliv, we have previously evaluated the potential of protective devices for motorcyclists in case-by-case analysis for severe and fatal injuries, showing that countermeasures can be effective.
Motorcyclist protection is a world-wide concern. About 28% of 1.35 million annual road traffic fatalities are motorcyclists. The share is especially high in South-East Asia (43%), according to the WHO Global status report on road safety 2018.
Critical thinker ( Managing Editor / Research Manager yada yada)
6 年Why are motorised pedestrians (motorcyclists) so much less likely to die hitting various objects than pedestrians struck by cars at the same speed? There seems to be a rather large gap between this report and the ITF's findings here:?https://www.itf-oecd.org/sites/default/files/docs/speed-crash-risk.pdf?
There are three factors that have to apply. Trajectory of rider,. Trajectory of bike bith with a random distribution within a cone the third factor is the distribution of obstacles which is fixed in any specific case we also need to add kinetic energy loss by friction if and not a rider bike separation. Only after these factors are set up does kinetic energy loss from a hard rider object collision apply. The latter is the only epidemiological factor and thus is the simple proxy for safety targeting. Ever since Fox and Joubert the trajectory/ impact distributions have been useful but rarely actually used by infrastructure for safety. A simple probabilistic simulation could provide a more nuanced approach but there are zero signs of any such work from a safety dominated profession. Ironically vision zero would readily support such an approach, but data collection priorities and culture seem to be an insuperable barrier fir the safety culture. Once again broad undifferentiated Public Health approaches(speed is all) is in conflict with many ethical and more sophisticated but demanding approaches.
CEO . Professional Inventor
6 年My dear friends.? We can dispute various ways and means to provide known accident avoidance to occur until the cows come home. ? Enough with mere state of? the art when "basic" new unknown knowledge is needed and is now available from me. ? For example when I say I can and I will possibly reduce motor cycle deaths and bicycle deaths at night by an estimated 50 percent please do not believe me until I can prove it. ? Not to worry, I will show you how soon when it is granted patent application status, and provide a show and tell in actual application to allow you to see it, and to allow accident avoidance to occur at the speed of light retro reflectively to even a tricycle of a child ,or his or her parents? motorcycle.? As an example of my prior work in this field is easy to understand.? Take a look at the picture that shows just a few of my proprietary advancements that allow SEEING to be a priority in accident avoidance. .? Click on the picture to enlarge. ?? Have a Happy New Year.?
PhD
6 年I really get a buzz disproving "experts".? Watch this from the Isle of Man TT - 2 minutes 25 seconds into the video.? The speed is 180 miles per hour.?? The point is folks - that the correlation of the severity of injuries and speed is RANDOM!? Watch and learn.? We need to have studies carried out by people who actually know the facts - i.e. motorcyclists, crash investigators and trauma doctors who attend road racing such as Isle of Man or Irish road racing.?? https://www.youtube.com/watch?v=ocHeJG5o8N0