Abstract
Frontal crash safety performance effects on belted drivers´ injuries in the real
world in Japan were analyzed for studying some directions in mitigating the injuries by each
part of human body.
The 1998-2002 model-year vehicles models with JNCAP test data, whose registered number
were more than 200,000 from the year of 2000 to 2004 for significant statistical analysis,
were selected. This threshold selected 15 models as compact vehicles, 31 models as all
categories models. The macro field accident data based on police data were compiled by
"Institute for Traffic Accident Research and Data Analysis (ITARDA)" at the request of us.
The lower-extremity injuries were mainly investigated by using the number of belted driver´s
fatal and serious injury whose maximum injury part was lower-extremity per 10,000
registered vehicles.
The relationships between lower-extremity injury rate in the real world and crash safety
performance parameters i.e., femur load, tibia index and intrusions of brake pedal, toe board
were elaborately analyzed by showing on scatter charts, examining coefficients of
determination and doing multi regression analysis. These intrusions were obtained by the
standardized tests, not by investigation into the actual vehicles in real accidents. The detailed
results of JNCAP full-wrap and offset frontal crash tests have been used to provide the values
of crash safety performances for each vehicle model.
As a result, the effects of right femur load, left lower tibia index, footrest and toe board
intrusions in full-wrap frontal crash test on lower-extremity fatal and serious injury rate in the
real world were clearly discernible in our investigation. The coefficients of determination; R 2
were 0.56, 0.54, 0.53, 0.78, respectively. The explicit relationships between left lower tibia
index and footrest intrusion etc. have been also successfully captured.
The effects of the crash safety performance parameters in full-wrap frontal crash test were
larger than those in offset frontal crash test. It has become evident that this tendency was due
to the fact that the accident with fatal and serious injury would happen more likely in the case
of crash to fixations and large trucks than in the case of car-to-car crash.
In addition, body decelerations and maximum crash stroke measured at the driver´s side sill
were calculated for characterizing the body crash safety performances. The abhorrent
relationships between crash stroke etc. and body intrusions were recognized afresh.
The present study has made great progress in capturing the essential crash safety performance
parameters related to lower-extremity fatal and serious injury rate, although overall analysis
including all part of human body injuries, for example, neck injuries, is necessary to
determine the actual vehicle specification.
Keywords: Accident Analysis, Passive Safety, Lower-extremity, Statistics, NCAP