A construction-related information estimation system includes a moving body correspondence information terminal configured to move together with a moving body that moves on a target road, the target road being a road on which a construction site that is a place which is estimated to be under a construction is located or that is located near the construction site, and transmit terminal information including a terminal ID signal that is its own identification information and its own position information, and an information processing device configured to have map information including information on the construction site and the target road and receive the terminal ID signal and the position information transmitted from the moving body correspondence information terminal. The information processing device is configured to estimate a current situation of the target road based on the terminal information and the map information acquired from the moving body correspondence information terminal.