Abstract
To prevent such dangerous situations, as the workers on the track are exposed to the risk of being hit by an oncoming train, JR West has developed and implemented a GPS-linked train approach alarm system and put it in practice. Under this system, each train lookout carries two mobile phones that automatically measure their position through the Global Positioning System (GPS). The phones trigger a train approach alarm attached to them if a train is detected on the track circuit specified in advance for each work site.
