Promotion of the development of safe driving support system with close collaboration between ITS engineers and social scientists

Since the first ITS World Congress was held in 1994, 14 years have passed. In this period in-vehicle navigation systems and the electronic toll collection (ETC) systems have been put into practice and now 30% of all passenger cars in Japan have equipped with in-vehicle navigation systems. Moreover many cars in Japan have equipped with in-vehicle ETC units and the infrastructure for ETC has been built at almost every toll gate. At very early stage of ETC popularization, people said that there was "chicken and egg arguments" between building ETC infrastructure at toll gates and spreading in-vehicle ETC units. They, therefore, worried about not spreading of ETC systems. But actually there was not any anxiety for spreading of ETC systems. On the contrary of this, safe driving support systems are not widely used in Japan as well as all over the worlds. Why are safe driving support systems not widely used? In this paper, necessity of the close collaboration between social scientists and natural scientists is proposed after our reviewing spare capacity model and the risk-homeo-stasis theory to explain both the relation between several characteristics of traffic accidents and human beings, qualitatively.