Provided is a forecasting device (100), comprising: an acquisition unit (101) which acquires from another vehicle a movement history of the other vehicle; a forecasting unit (102) which forecasts the behavior of the other vehicle on the basis of the movement history; and an output unit (103) which outputs driving assistance information on the basis of the forecast. The acquisition unit (101) acquires the movement history from the other vehicle within a communication range of vehicle-to-vehicle communication, and the forecasting unit (102) forecasts the behavior of the other vehicle within the communication range of the vehicle-to-vehicle communication. The acquisition unit (101) acquires information which may be used in the forecasting of the behavior of the other vehicle, and the forecasting unit (102) forecasts the behavior of the other vehicle , using a plurality of instances of the information together with the movement history.
