Abstract:
Physical tests were performed with a bicycle and a dummy in a controlled laboratory
environment to reproduce cyclist accidents. The kinematics of 13 sled tests were used to
identify the cyclist head impact location, understand the interaction between the cyclist
and bicycle and to validate a mathematical model.
The finite element software code LS-DYNA was used to simulate 70 cyclist and
pedestrian accidents with motor vehicles with four different vehicle shapes which
supplemented the physical testing. The study has shown that when cyclists and
pedestrians were struck by any of the vehicles their whole body kinematics can be
distinguished into two phases, initially a rotation followed by a sliding action. The Sports
Utility Vehicle (SUV) vehicle produced more of a rotation action rather than sliding,
whereas the other vehicles produced a combination of the two.
The current pedestrian legislation does not cover all head impact locations for cyclists
and therefore needs to be extended to encompass the windscreen and A-Pillar regions of
the vehicles. The wrap around distance (WAD) for all the vehicles, apart from the SUV,
should be extended to encompass a larger region. For the SUV the current WAD region is
adequate in protecting cyclists and pedestrians and does not need to change. The
predicted head impactor angle for cyclists is 40 degrees which is lower than the current
legislative value of 65 degrees and the predicted pedestrian head impact angle is higher at
a value of 80 degrees for the MPV, SM and LFC. For the SUV the proposed impactor
angle increased to 100 degrees for cyclists and pedestrians.
This research has demonstrated significant differences in terms of input variables and
outcomes between cyclist and pedestrian accidents involving vehicles. It has used
mathematical models to obtain injury data from a human mathematical model and
physical testing to replicate real world cyclist accident scenarios. Recommendations have
been proposed for future legislative testing techniques for cyclists, based on existing
pedestrian legislation. These recommendations to alter legislation will improve vehicle
design and make future vehicles more cyclist-friendly.