On-board device and route interpolating method therefor

An object of the present invention is to interpolate a discontinuous zone by use of an appropriate interpolated route in terms of fee-charging. An on-board device includes a map information storage unit storing map information in which a road is divided into a plurality of line segments in a pseudo manner and each of the divided line segments is made to correspond to unique identification information and the positional information, and an interpolated route information storage unit storing interpolated route information in which a combination of two discontinuous line segments and a line segment constituting an interpolated route for connecting the former line segments are uniquely defined, in which a moving route creation unit uses the interpolated route information to interpolate the discontinuous zone in a case where two line segments consecutively specified by a link specifying unit are discontinuous on the map information.