DRIVING SUPPORT DEVICE, VEHICLE, DRIVING SUPPORT METHOD, AND STORAGE MEDIUM

The present invention provides a driving support device that performs driving support of a vehicle, comprising: a speed detector configured to detect a speed of the vehicle; and a controller configured to control lane change support from a traveling lane in which the vehicle travels to an adjacent lane, in a case where the speed of the vehicle detected by the speed detector is equal to or greater than a threshold, wherein the controller is configured to execute the lane change support even when the speed of the vehicle detected by the speed detector is lower than the threshold, in a case where a predetermined condition is satisfied, and the predetermined condition includes a condition that the lane change support is executed in a start area of a new lane adjacent to the traveling lane that increases the number of lanes.