CONTROL DEVICE AND CONTROL METHOD

The present disclosure obtains a controller and a control method capable of performing an adaptive cruise control appropriately during a group ride.A controller (20) and a control method according to the present disclosure performs an adaptive cruise control, using an execution section of the controller, based on a surrounding environment information around a motorcycle (1). An acquisition section of the controller (20) acquires an image data based on a detection result output from a camera (15) mounted to a subject vehicle (1). The image data captures another vehicle traveling in a group ride in which a group of motorcycles including the subject vehicle (1) and the other vehicle is traveling in a group. An identification section of the controller (20) identifies the other vehicle based on the image data acquired by the acquisition section. The execution section executes a group ride mode, which is a mode of the adaptive cruise control and is executed during the group ride, based on a travel state information of the other vehicle identified by the identification section.