An autonomous vehicle has a temperature sensor for sensing an air temperature or a road temperature, a processor communicatively connected to the temperature sensor to receive a signal from the temperature sensor, to process the signal and to generate an estimated instantaneous coefficient of friction between a tire of the vehicle and a snow-covered roadway, and a camera to detect salt and/or sand on the roadway and to apply a salt correction factor and/or a sand correction factor to the coefficient of friction to thereby provide a salt-corrected coefficient of friction or a sand-corrected coefficient of friction.