An autonomous driving vehicle provides a driverless transportation service for a user. An alarming phenomenon is a natural phenomenon that potentially causes a disaster. The autonomous driving vehicle recognizes, based on driving environment information, the alarming phenomenon at a current location of the autonomous driving vehicle or on a planned travel route from the current location to a destination. When recognizing the alarming phenomenon, the autonomous driving vehicle determines whether to continue or halt vehicle travel control in accordance with a current travel plan. When determining to halt the vehicle travel control in accordance with the current travel plan, the autonomous driving vehicle sets an emergency plan depending on a type of the alarming phenomenon and controls the autonomous driving vehicle in accordance with the emergency plan.