 At the end of the war, the system was so worn that thought was given as to how to renovate it.Rubber-tyred metro technology was first applied to the Paris Métro, developed by Michelin, who provided the tyres and guidance system, in collaboration with Renault, who provided the vehicles.Starting in 1951, an experimental vehicle, the MP 51, operated on a test track between Porte des Lilas and Pré Saint Gervais, a section of line not open to the public.