Abstract: The present disclosure relates to an apparatus (100) for estimating a road condition. The apparatus (100) comprises an input interface (110) configured to receive input data (112) derived from one or more sensors, wherein each sensor is configured to measure a physical quantity related to a vehicle (200) or its environment, wherein the input data (112) features a current driving status of the vehicle, a machine learning processor (120) configured to map the input data (112) to an estimated road condition (122), and a validation processor (130) configured to validate the estimated road condition (122) based on a measurement (132) of the road condition obtained at the current driving status of the vehicle. Validation information from the validation processor (130) can be transmitted to a cloud server (170) for further processing and producing validation swarm knowledge for a whole vehicle fleet.