Provided is a same vehicle detection device, including: a first license plate information acquisition unit configured to store, in a first recording unit, first license plate information acquired from an onboard unit installed in a vehicle; a second license plate information acquisition unit configured to store, in a second recording unit, second license plate information of the vehicle read in, based on an image captured by shooting a predetermined region including the license plate of the vehicle; and a same vehicle determination unit configured to determine whether the first license plate information stored in the first recording device relates to the same vehicle as the second license plate information stored in the second recording device.