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', and the task 1.2, 'In depth Motorcycle Accident Investigation' aim 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. This deliverable, D1.3 represent a summary of the main findings of WP1. The analysis of the literature and the successive in-depth accident study show that there is a lack of data and there is a need for more in-depth PTW’s accident studies. Another important aspect is that in about 50% of the PTW accidents against a road restrain system, the rider is still in an upright riding position when the impact occurs, with the associated risks of being thrown on or over the barrier. Currently, this scenario is not considered in existing standard and is not included in the draft standard for protective road restraint systems approved by Technical Group 1 of CEN (European Committee for Normalisation). Moreover, very few studies have been performed to assess this scenario up to now. This configuration represents a scenario to be considered in future work. 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 which can seems a small figure. However, a fatal outcome is 2 to 5 times more likely for an impact with a crash barrier than for motorcycle accidents in general. According to the literature review, 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. However, the in-depth study has demonstrated that larger impact angle are also possible and must be taken into account 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. The best 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 Barriers 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. In the majority of accidents the PTW's speed tend to be very high, especially in the case of the fatal ones. (Author/publisher)
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