An approach is provided for providing lane-level connectivity data at an intersection. The approach involves, for example, retrieving probe data for an intersection with at least one upstream road link and at least one downstream link. The approach also involves performing a lane-level map-matching of the probe data to one or more upstream lanes of the at least one upstream road link, one or more downstream lanes of the at least one downstream link, or a combination thereof. The approach further involves generating a junction matrix for the intersection between the one or more upstream lanes of the at least one upstream road link and the one or more downstream lanes of the at least one downstream road link based on the lane-level map-matching of the probe data. The approach further involves determining lane-connectivity data for the intersection based on the junction matrix.