1. A field watch apparatus for use by a subject vehicle comprising: a plurality of road image acquisition units, each being disposed at respective predetermined intervals from each other on respectively associated structures fixedly situated with respect to the earth along a vehicle roadway and being configured to acquire at least a first road image that includes the subject vehicle from a first of said road image acquisition units and a second road image, different from the first road image, that includes a front or a rear field view relative to the subject vehicle from a second of said road image acquisition units; an overhead view generation unit configured to generate an overhead view of the subject vehicle with a viewpoint from above the subject vehicle, wherein the overhead view of the subject vehicle is generated as a view of a real image of a nearby area of the subject vehicle by composing at least the first road image and the second road image; and a display unit disposed in the subject vehicle and configured to display the overhead view of the subject vehicle, wherein a position of the subject vehicle is represented in an identifiable manner in the overhead view.