A method and system for providing a drowsiness alert to a driver of a vehicle are described. A drowsiness estimate data set is compared to historical drowsiness data from multiple vehicles. The drowsiness estimate data set includes current drive context data, and traffic situation data indicative of a present traffic situation for the vehicle and the position of the vehicle. The previously collected drowsiness estimate data sets of the historical drowsiness data are each associated with a determined degree of drowsiness of the respective driver when the previous drowsiness estimate data sets were collected. The degree of drowsiness is determined by a drowsiness detection system in the respective vehicle. A drowsiness risk measure is subsequently determined and, based on the drowsiness risk measure and based on a current drive context for the vehicle, a drowsiness alert may be provided to the driver.