1. A road estimation device configured to receive data including a plurality of core points from an external object, the core points being assigned along a road and being respectively assigned with attributes for identifying the road, the road estimation device further configured to extract links pertinent to the road represented by the core points for estimating the road on a map, the road estimation device comprising: a map data input unit configured to input map data including links respectively having attributes corresponding to the attributes of the core points; a link extraction unit configured to extract candidate links, which are candidate of the road represented by the core points, correspondingly to each of the core points, from the map data according to the attributes of the links and the attributes of the core points; and a road estimation unit configured to implement a road search processing to: extract an start-side core point and an end-side core point being adjacent to each other from an array of the core points; and search a link pertinent to a road, which connects a start-side candidate link with an end-side candidate link, the start-side candidate link and the end-side candidate link being extracted by the link extraction unit and being respectively corresponding to the start-side core point and the end-side core point, the road estimation unit being further configured to estimate a road on the map from the start-side core point to the end-side core point according to the searched link.