Life Trail is a directional and escape system that leads people to shelters quickly in an emergency situation. It combines functions of traffic signs and emergency routes, and it’s a general traffic signs at peacetime in the city. It will activate automatically when a disaster warning alert signal from “Disaster Prevention C enter” by satellite, and then start to plan the most efficient route. The general raffic signs will convert into the evacuation sign with warning sound immediately. Meanwhile, the arrow will rotate to guide people to the nearest shelter.