Abstract
Common underground ducts were adopted in the Tokyo Reconstruction Project as a means to bury electric lines on poles above ground and to re-organize utility lines under ground. Though the common ducts were effective to rearrange materials which were buried under ground, there were some issues to be solved such as budget for the enormous cost and harmonization among participating business entities (of power, communication etc.). In addition, it was provided in the Road Act that the facilities which accommodate road occupying structures were out of control of road administrators, and the facilities were recognized as road occupying structures. After enactment of the Common Duct in 1963, the Road Act was partially revised to change the status of road occupying structure to a fixture to roads. In the Cable Underground Laying Project which was started in 1986, a variety of methods (cable box, dusts controlled by a autonomy, common electric line ducts) were used to bury electric lines under ground, and each of their legal categories differs depending on the methodology.This Paper chronologically clarifies how the circumstances have been matured to expedite the burying of electric lines under ground, reviewing the transition of legal status of the common ducts in Japan.
