The conditions for diffusion of car navigation system for ITS World Congress Busan 2010

The diffusion rate of car navigation system, one of accessible ITS devices, has already reached 45.7% (e.g. (1)) in Japan, while it still stays at 11.3% (e.g. (2)) in the world. The diffusion rate, however, is expected to increase up to 27.7% by 2012(e.g. (2)) with the expansion and wide adoption of the technology in the world. At the same time, there are no previous studies forecasting the regions where the car navigation system would become widespread. In this study, therefore, we would like to find out the necessary conditions for diffusion of car navigation systems by comparing the diffusion rates of car navigation system, the total road length, the number of registered cars, and the average income in each prefecture in Japan. In addition, by looking at the region with the effective use of car navigation system or with specific needs for the use of car navigation system, we would like to draw recommendations for improvement of efficiency of urban traffic all over the world.