A method for validating an inland water barrier crossing specification in a digital map by observing local probe data, said method comprising the steps of: providing a digital map having at least two road segments (18,20) separated from one another by an inland water barrier; reporting data from a plurality of probe traces traveling the at least two road segments (18, 20) in the vicinity of the inland water barrier, the reported data including velocity information or enabling the derivation of velocity information; identifying barrier crossing probe traces that traverse the inland water barrier crossing from one road segment to the other road segment; and computing a velocity average for the barrier crossing probe traces; characterized by: establishing a crossing speed threshold value; inferring by a digital map database editor a bridge linking the two road segments (18,20) across the inland water barrier if the velocity average for the barrier crossing probe traces is GREATER than the crossing speed threshold value, and inferring a ferry linking the two road segments (18,20) across the inland water barrier if the velocity average for the barrier crossing probe traces is LESS than the crossing speed threshold value; and altering the digital map, as needed, to designate a bridge or a ferry interconnecting the two road segments (18,20) across the inland water barrier based on said inferring steps. providing a digital map having at least two road segments (18,20) separated from one another by an inland water barrier; reporting data from a plurality of probe traces traveling the at least two road segments (18, 20) in the vicinity of the inland water barrier, the reported data including velocity information or enabling the derivation of velocity information; identifying barrier crossing probe traces that traverse the inland water barrier crossing from one road segment to the other road segment; and computing a velocity average for the barrier crossing probe traces; characterized by: establishing a crossing speed threshold value; inferring by a digital map database editor a bridge linking the two road segments (18,20) across the inland water barrier if the velocity average for the barrier crossing probe traces is GREATER than the crossing speed threshold value, and inferring a ferry linking the two road segments (18,20) across the inland water barrier if the velocity average for the barrier crossing probe traces is LESS than the crossing speed threshold value; and altering the digital map, as needed, to designate a bridge or a ferry interconnecting the two road segments (18,20) across the inland water barrier based on said inferring steps. establishing a crossing speed threshold value; inferring by a digital map database editor a bridge linking the two road segments (18,20) across the inland water barrier if the velocity average for the barrier crossing probe traces is GREATER than the crossing speed threshold value, and inferring a ferry linking the two road segments (18,20) across the inland water barrier if the velocity average for the barrier crossing probe traces is LESS than the crossing speed threshold value; and altering the digital map, as needed, to designate a bridge or a ferry interconnecting the two road segments (18,20) across the inland water barrier based on said inferring steps.