Abstract
Next-generation VICS services that provide useful information to drivers are scheduled for launch in April 2015, following FM multiplex broadcasting band extension. One of the new services includes roadway hazard warning, especially under heavy rainfall conditions, which provides alerts through automatically converting raster rainfall data to vector data and superimposing it onto a digital map displayed on the car navigation display. This research is the first to take up "rainfall intensity experienced by a running vehicle" while previous researches have not explicitly did. In addition, we make a unique step toward the promotion of drivers’ prior actions for avoidance, utilizing "rainfall intensity experienced by a running vehicle". In this research, a threshold for XRAIN rainfall information is defined at 50mm/h, and a rainfall estimation method using XRAIN rainfall information is proposed, taking the vehicle speed into consideration.
