Abstract
In Japan, fatal accidents in which persons are sometimes caught in heavy- duty trucks when the trucks turn left became a big social problem starting around 1976. In Japan, the driver's seat is usually on the right hand side. The analysis result of the accidents showed that it will be effective in reducing the accidents to improve the visibility to the left and to prevent persons from being caught under truck rear wheel. To remedy the situation, the introduction of regulations was considered which requires the improvement of indirect visibility (visibility through mirrors), betterment of the pedestrian protection side guard, addition of the direction indicator lamp at the middle of the vehicle side.