In the 1970's, when constructing buildings in the neighbourhood of Defense, Public institution for the development of the region of Defence (EPAD) already provided an extension of the line 1 to the west, it therefore reserved a space in the foundations of buildings that would build two stations, La Defense - Michelet, and Elysees La Defense. In 1992, when it actually lasted RATP metro line, it rejected a passage in the Seine, assumed 20 years earlier by the EPAD. It is preferable to build above the Seine using the Pont de Neuilly.