An approach is provided for automatically verifying a road closure using multiple possible vehicle paths between two probe points. The approach involves, for example, processing probe data to determine a possible path of a vehicle over a road graph, wherein the road graph represents a road link and one or more other road links entering or exiting the road link. The approach also involves calculating a path probability for the possible path, wherein the path probability indicates a likelihood that the possible path is a true path of the vehicle over the road graph. The approach further involves assigning a weighted vehicle count to the road link and/or one or more other road links contained in the possible path, wherein the weighted vehicle count is based on the path probability. The approach further involves detecting a traffic anomaly occurring on the road link based on the weighted vehicle count.