An automatic driving system includes an electronic control unit. The electronic control unit is configured to create a traveling plan including a control target value of automatic driving control of a vehicle based on a position of the vehicle of a map, a vehicle state, and an external environment, to calculate an abnormality value, to determine, based on the abnormality value, whether the vehicle is an a normal state, an abnormal state, or an intermediate state, and to create an abnormal traveling plan as the traveling plan when it has been determined that the vehicle is in the abnormal state.