Abstract
The improvement of traffic safety is one of the major goals of Intelligent Transportation Systems. A driver support system for preventing a collision with an forward obstacle has been developed as a part of Advanced Cruise-Asist Highway Systems. The performance of the developed forward obstacle collision avoidance system was measured using a driving simulator and by a field test and the effectiveness was verified. Then, this system has been installed at Sangubashi curve of the Metropolitan Expressways since 2005 and the number of traffic accidents were recorded before and after the installation. This paper describes the requirements needed in the elemental technologies for the system and how to meet these requirements. The contributing factors that realized drastic reduction in the number of accidents have been analyzed and it was found that the information provision by a variable message sign is very effective in improving traffic safety. Reconstruction of the road surface and the information provision by VICS were found to be less effective. However, the effect of the information provision service will be stronger if the dissemination rate rises.
