'Shuttle') was a single-track shuttle that operated between Porte des Lilas and Pré Saint-Gervais, using the titular Voie Navette.

[3] The shuttle first operated from 27 November 1921 to the outbreak of World War II on 2 September 1939, with a single train running back and forth between the two stations on the Voie Navette.

After the war, the RATP reopened the shuttle as a prototype rubber-tyred metro line from 13 April 1952 to 31 May 1956, with a single MP 51 car running back and forth as well.

Although the CMP completed the connecting lines and the platforms of Haxo and Porte des Lilas, it never fully opened the extension.

Therefore, Louis Blanc station would no longer be the western terminus of the line, but that would require the creation of a new tunnel and extensive works.