A straddle type vehicle includes a setting unit configured to set a warning line along a boundary between a traveling lane of a self-vehicle and an oncoming lane, a warning unit configured to issue a warning if the self-vehicle has crossed the warning line, a detection unit configured to detect a difficult-to-travel region in the traveling lane, and a determination unit configured to determine whether it is difficult or possible for the self-vehicle to pass between the boundary and the difficult-to-travel region. If it is determined by the determination unit that it is difficult for the self-vehicle to pass, the setting unit changes a position of the warning line to a position shifted from the boundary toward the oncoming lane side.