This paper presented a part of results from an ongoing project
for pedestrian protection, which is carried out at Chalmers
University of Technology in Sweden. A validated pedestrian
mathematical model was used in this study to simulate
vehicle-pedestrian impacts. A large number of simulations have been
carried out with various parameters. The injury-related parameters
concerning head, chest, pelvis and lower extremities were
calculated to evaluate the effect of impact speed and vehicle front
structure on the risk of pedestrian injuries. The effect of
following vehicle parameters was studied: stiffness of bumper, hood
edge, hood top, windscreen frame, and shape of vehicle front
structures. A parameter study was conducted by modelling
vehicle-pedestrian impacts with various sizes of cars, mini vans,
and light trucks. This choice represents the trends of new vehicle
fleet and their frequency of involvement in real world accidents.
The mechanical properties of the vehicle front were based on the
available data from EURO NCAP tests, and from published
literature.
Based on the results from the simulation study, possible
benefits from speed control in urban area can be assessed. As the
impact speed decreases from the 40 to 30 km/h, the probability of
severe head injury will decrease from 50% to lower than 25%.
The influences of the various compliance and geometric
parameters of vehicle front are analyzed. The most significant
parameters to pedestrian impact protection are clarified,
especially for head and lower extremities. A procedure in new
vehicle-front design is presented, which can lead to a design
guideline of safer vehicles for pedestrians.
Furthermore, gaps in pedestrian protection are identified, and
the research priorities should be focused on the adult head and
lower extremities and child head and thorax injuries.