ESTIMATION APPARATUS FOR WATER FILM THICKNESS ON ROAD SURFACE

An estimation apparatus for a water film thickness on a road surface includes a data acquisition unit and an estimation unit. The data acquisition unit sequentially acquires a data set including driving force data representing a driving force output from a driving source of a vehicle and acceleration data representing a longitudinal acceleration of the vehicle, while the vehicle is traveling. The estimation unit estimates a thickness of a water film on a road surface on which the vehicle travels, based on a relationship between a speed of the vehicle and a fluid resistance that the vehicle receives from the water film, the flow resistance being calculated based on the data set.