Passive safety for motorcyclists with particular regard to roadside impacts

The peculiarities of motorcycles bring significant risks for riders’ health in case of accident. In fact they have not got any safety cage as cars have and, when an accident occurs, the rider is more likely to suffer severe injuries than a car occupant. In addition, motorcycles do not feature any system capable of restraining the rider during an accident. A motorcyclist is therefore likely to face direct impacts against roadside objects. In such a situation, two possibilities exist to reduce the motorcyclist’s harm: reduce the dangerousness of the roadside obstacles or provide the rider’s garments with the capability of mitigating the consequences of the impact. This research activity concerns both of these possible approaches, studying biker protection systems mounted on the roadside barriers and wearable airbag devices. As a preliminary activity, the behaviour of Anthropomorphic Test Devices and the likelihood of their numeric models are investigated in off-design conditions, similar to those conditions that are typical of some motorcycling accidents. Thereafter, numeric models of three different additional barriers to be mounted on road restraint systems have been created and validated against experimental data. These models were used for sensitivity studies on characteristic impact parameters and for a critical review of the evaluation Standard for such devices. Finally, two scenarios were conceived to numerically evaluate the performance of an airbag device and to improve its design. Information provided by numeric simulations was confronted with experimental data. Both, safety devices mounted on roadside restraint systems and wearable airbags resulted capable of reducing the harm suffered by a motorcyclist that falls from his vehicle, slides on the ground and hits a standing object. An airbag device provides a more general protection; the air cushion around the neck reduces its movements, also contributing to reduce the head acceleration. The more specific road barriers instead also prevent the motorcyclist from trespassing the barrier itself, being exposed to further dangerous situations.