VEHICLE CONTROL METHOD AND VEHICLE CONTROL DEVICE

The controller 20: determines whether or not a current position of an own vehicle (1) is within a high-definition map-available region (Rav) in which high-definition map information (13H) is available; when determining that the current position of the own vehicle is within the high-definition map-available region (Rav), performs acceleration/deceleration control to control acceleration or deceleration of the own vehicle, based on specified speed information acquired by recognizing a speed sign in a captured image or specified speed information acquired from the high-definition map information (13H) based on the current position of the own vehicle and also notifying a driver of the specified speed information; and when the own vehicle is predicted to leave the high-definition map-available region (Rav) to the outside, terminates the acceleration/deceleration control based on the specified speed information and also acquires specified speed information from road map information (13N), the road map information having lower precision than the high-definition map information (13H), based on the current position of the own vehicle and notifies the driver of the acquired specified speed information, at a point (Pc) before a point (Po) at which the own vehicle leaves the high-definition map-available region (Rav) to the outside.