Abstract
Now, in the 21st century, the safety function for automobiles is dramatically improved. In 1970, the number of fatalities by the traffic accident decreased to 4 thousands since 1952. However, the number of fatalities is afraid to turn up to increase in the future aged society because half of all fatalities are accounted for by elderly people. So, it is absolutely necessary to improve the safety function furthermore. In this study, a front vehicle collision accounting for 70 percents of fatal accidents is treated, and an analytical model for human response due to front collision is established. Furthermore, an impact force reduction is studied by optimizing parameters of the vehicle with using genetic algorithm.