An approach is provided for determining one or more varying decay rates associated with one or more road segments. The approach involves causing, at least in part, a decaying of real-time traffic data to historical traffic data associated with the one or more road segments based, at least in part, on the one or more varying decay rates. The approach also involves determining one or more traffic predictions for the one or more road segments based, at least in part, on the decaying of the real-time traffic data to the historical traffic data.