Abstract: A vehicle includes a navigation device, and a controller electrically connected to the navigation device, wherein the controller is configured to determine a first speed of the vehicle based on a main line speed limit of a road on which the vehicle is traveling, wherein the main line speed limit is included in navigation information output by the navigation device, determine a second speed for decelerating the vehicle to a predetermined speed when the vehicle is positioned at a target point of a curved lane based on an arc length from a branching point of the road to the curved lane, which is determined based on the predetermined speed and a predetermined allowable maximum deceleration amount in the curved lane in route information included in the navigation information and the navigation information, and determine the first speed or the second speed as a control target speed of the vehicle at the branching point.