CONTROLLER AND CONTROL METHOD

The present disclosure provides a controller and a control method that execute an adaptive cruise control appropriately in a group riding.According to the present disclosure, an execution section (22) of a controller (20) executes an adaptive cruise control based on a surrounding environment information that is information about a surrounding environment of the motorcycle (1). The execution section (22), in the adaptive cruise control, controls a speed of the motorcycle (1) automatically regardless of an accelerating/decelerating operation by a rider of the motorcycle (1) and executes a distance maintenance control to keep a distance between the motorcycle (1) and a target vehicle at a target distance. An identification section (23) of the controller (20) identifies a first convoy including the motorcycle (1) in a group riding in which the motorcycle (1) travels in a group of a plurality of motorcycles (2) forming at least the first convoy and a second convoy separated from each other. The execution section (22) executes the adaptive cruise control based on a first travel state information about a travel state of a second motorcycle, the second motorcycle is one of the plurality of motorcycles (2) and is in the second convoy.