The objective of the “Innovative concepts for smart road restraint systems to provide greater safety for vulnerable road users” (Smart RRS) project is to reduce the number of injuries and deaths caused by road traffic accidents to vulnerable road users such as motorcyclists, cyclists and passengers through the development of a smart road restraint system. Within the WP1 'Characteristics of severe road traffic accidents concerning vulnerable road users such as motorcyclists' the task 1.1, 'Literature Review on Motorcycle Accidents', aims at identifying the characteristics of motorcycle and other vulnerable road user accidents, in general, and in particular to search for the main characteristics of those accidents where motorcyclists get injured because of contact with fixed objects, on the side of the road, or with the road restraint systems. To characterize the main parameters of these accidents: range of speeds at the point of impact, angles of impact, frequency of injuries by body region, etc. To know the physiological thresholds of the tolerance of the human body (or injury criteria) in the injured regions. The analysis of the literature shows that the majority of studies are based on small data sets and there is a need for more in-depth PTW’s accident studies. However, the available studies show that the impact of motorcyclists against a fixed object occurred in 4% of the cases in urban areas while it varies between 10% and 20% in rural areas. Despite absolute figures are not available, we can estimate that several hundreds of motorcyclist die every year in Europe because of an impact against the infrastructure, mainly trees/poles, roadside barriers and road infrastructure in general. Most motorcycle collisions with crash barriers occurred at shallow angles (typically between 10° and 45°) with the rider typically sliding into the barrier at a bend. According to different studies, a fatal outcome is 2 to 5 times more likely for an impact with a crash barrier than for motorcycle accidents in general. The most dangerous aspect of guardrails with respect to motorcyclists is the exposed guardrail posts: An impact on a post can, depending on the part of the body involved, cause fatal injuries at an impact velocity of as low as 20km/h. For sliding motorcyclist, it appears clear that discontinuous systems are worse than continuous. In this scenario, post modifications together with post envelopes shows a positive approach in decreasing risks for motorcyclists. A much better solution seems to be the addition of a lower rail. As this provides better energy absorption than concrete solutions or wire rope safety barriers. Wire Rope Safety Barrier are viewed by motorcyclists as the most aggressive form of RRS. This view is supported by computer simulations and tests, which indicate that injuries will be severe if a rider hits the cables or the support. Eventually, it must also be considered that the impact scenario in an upright riding position seems to be equally important, with the associated risks of being thrown on or over the barrier, and this scenario has not be investigated in depth up to now. (Author/publisher)
Abstract