Disclosed is a toilet bowl water level gauge and associated methods. The microcomputer calculates the optimal shift timing subject to the time point the crank to be moved over the pedaling dead point in the next time, the pedaling speed to be below a predetermined speed value or the cranks are been pedaling backwardly. A bottom surface of an inner peripheral edge portion of a conductive damper disposed on an upper side in plural dampers is fixed to the connecting member with adhesive applied to the groove. In terms of each individual still object group, the process selects a left or right evaluation map depending on whether the still object group is positioned to the left or right side of a road.