An approach is provided for node-based map matching. The approach involves processing probe data to sort a plurality of probe points according to sessions keys. The approach also involves selecting a subset of the plurality of probe points within a threshold distance of a node of a map representation of a transportation network. The approach further involves initiating a map matching of the probe points of each session key to the map representation by, for said each session key: (1) determining a closest probe point to the node; (2) determining another closest probe point to a neighboring node, wherein the neighboring node is connected to the node by at least one link; and (3) projecting the plurality of probe points between the closest probe point to the node and the another closest probe point to the neighboring node onto the link.