Computation apparatus and vehicle

An on-vehicle computation apparatus, comprising a first detection unit configured to detect a travelable route on which a self-vehicle is travelable, a second detection unit configured to detect a driving operation input to the self-vehicle, the driving operation including a steering operation, a steering assist unit configured to assist the steering operation so that the self-vehicle travels along the travelable route detected by the first detection unit, a specification unit configured to specify one of two or more travelable routes based on the driving operation, when the two or more travelable routes are detected by the first detection unit, and a control unit configured to control the steering assist unit and to, when the two or more travelable routes are detected by the first detection unit, suppress the assist by the steering assist unit until one of the two or more travelable routes is specified by the specification unit.