An approach is provided for creating an origin-destination matrix from probe trajectory data. The approach includes determining, via an outdoor positioning system, that at least one probe device has entered a point-of-interest (POI). The approach also includes initiating an indoor positioning system to determine indoor location data associated for the at least one probe device while the at least one device is within the POI. The approach further includes processing the indoor location data to generate an origin-destination (OD) matrix. The OD matrix represents an indoor movement of the at least one probe device among a plurality of sub-POIs located within the POI indicated by the indoor location data. The approach further includes providing the OD matrix as an output.