In order to maintain a smooth and safety traffic environment, what information an autonomous vehicle should show toward pedestrians was considered.　An unmanned experiment vehicle which was K-car size equipped with a large display was prepared, and psychological experiments were conducted assuming a pedestrian is about to cross in front of an autonomous vehicle.　The results showed that it is effective to tell that the autonomous vehicle recognizes pedestrians, to tell pedestrians how the autonomous vehicle will behave in the future, and to inform pedestrians using figures and symbols.　These fundamental findings are expected to be the basis of applied research and development toward realizing a safe, secure autonomous driving society including not only automobiles but also pedestrians.

　This cross-sectional study assessed quantitative differences in school student traffic accident injuries and fatalities during commuting to school and private traffic according to students’ year of study in school.　We created the working hypotheses presented below.

　・Immediately after entering a higher grade at a different school, student patterns of school commuting and private daily life activities extend and vary.　The different activity patterns engender sudden increases in opportunities for passage through new and unfamiliar road environments, thereby increasing student traffic casualties.

　・As school years advance, students gradually learn and become accustomed to new road environments.　In addition, their cognitive functions develop gradually.　These bring a gradual decrease in student traffic casualties.

　Using a Japanese national traffic accident database, the numbers of student casualties per 100,000 population during April 2013-March 2018 were analyzed for students of elementary school through senior high school.　A tendency showed that student casualties during the first year after entering a school of higher grade were more numerous than those of the prior academic year. Student casualties became fewer as the school years advanced.　These results partially support the hypotheses presented above.