To avoid and restrain deflection of a handle by predicting or detecting the deflection caused by a road shape of a traveling road and reduction of a pneumatic pressure of a tire.

A handle controlling device 10 collects information on traveling of a vehicle, and assists an operation of a vehicle based on the collected information. A CCD camera 11 and a pneumatic pressure sensor 13 detect deflection factors causing the deflection of a handle, and a handle deflection predicting and detecting part 116a predicts and/or detects the deflection of the handle based on the detected deflection factors. A handle deflection avoiding and controlling part 116b or a handle deflection restraining and controlling part 116c avoids or restrains deflection based on the output of the deflection predicting and detecting part 116a.