Paris Métro Line 1 is one of the sixteen lines composing the Paris Métro (in Paris, France). It connects the La Défense – Grande Arche and Château de Vincennes stations. With a 16.5 km length, it constitutes an "East-West" route transportation important for the City of Paris. Excluding RER (French: Réseau Express Régional) lines, it is the most utilised subway line on the network with 213 million travellers in 2008 and 725,000 people per day on average.
Line 1, as indicated by its name, was the first one to open, its first section opened in 1900. It is also the first line on the network to be converted from a manually driven operation to a fully automated operation. Construction, which commenced in 2007 and was completed in 2011, included new rolling stock, the MP 05, and laying of platform edge doors in all stations. The first eight MP 05 trains (#s 501 through 508) went into passenger service on November 3, 2011, allowing the accelerated transfer of the existing MP 89CC stock to line 4. The conversion allowed Line 1 to operate as the system's second fully automated line, after Line 14.
A transition to fully automated services was done without major interruption to passenger traffic, and the new MP 05 rolling stock was able to operate efficiently alongside the manually-driven MP 89 CC rolling stock until there were enough MP 05 to no longer facilitate the need of the MP 89. Full automation was achieved for evening services in May, 2012, with an increase to weekend services by August, 2012. As of December 15, 2012, Line 1 is 100% automated, with only a few MP 89 CC trains being used during rush hours when needed. The remaining 5 trains will remain stored on Line 1, near the Fontenay workshops, until a new garage for Line 4 is opened, south of the new Mairie de Montrouge station, in February, 2013.