A road estimation device receives data including core points assigned along a road and assigned with attributes for identifying the road. An input unit inputs map data including links in a unit of a divided region. Each link has a termination point in a boundary of the divided region. The links have attributes corresponding to attributes of the core points. When the core points exist beyond a boundary of the divided region, a generation unit generates a virtual core point on the boundary in the inputted map data and assigns an attribute to the virtual core point based on the attributes of the core points. An extraction unit extracts a candidate link being candidate of the road from the map data according to the attributes of the links, the core points, and the virtual core point.