Due to greater traffic density and congestion, traffic accident in Japan has becn increasing in past five years. We can mention three main factors in this increasing trend by analyzing accident data in Japan. These factors are:​

1. Motor vehicle occupant deaths have been increased slightly and continue to make a large proportion of the number of total deaths.
2. The elders deaths have been increasing continuously.
3. Moped riders and motorcyclists deaths have been increased dramatically, which is the biggest factor of the above trend.

Therefore, strong countermeasures are needed such as follows;​

1. Promotion of seat belt use including compulsory measures,
2. Systematic traffic safety education for elderly people,
3. Comprehensive traffic safety measures for mopeds and motorcycles.

Especially for safety measures for mopeds and motorcycles, we investigate comprehensively and make some proposals.