ROAD SURFACE STATE PREDICTION METHOD AND ROAD SURFACE STATE PREDICTION SYSTEM

The invention provides a method for accurately predicting a road surface condition at a location within a predetermined range. To that end, the road surface conditions at the location within the predetermined range are predicted using road surface estimation decision values calculated using vehicular information, which is the information on the behavior of a vehicle W i during travel obtained by an on-board sensor mounted on the vehicle, or estimated road surface conditions estimated using the road surface estimation decision values. In doing so, the road surface condition at the location within the predetermined range is predicted based on the road surface estimation decision values calculated for the location within the predetermined range or the time-dependent changes in the estimated road surface conditions.