First known as the Regional Metro when inaugurated in 1969, the RER A is a major transport axis for the Ile-de-France region. It forms a vital link between dense residential areas and the main employment areas, including the Auber-Saint-Lazare-Haussmann business triangle and the La Défense business district. With passenger traffic increasing almost continuously, the RER A is one of the world’s most heavily travelled rapid transit lines.

Published on 28 March 2017

6 July 1961: Groundbreaking ceremony for construction of the Étoile – La Défense segment at Ile de Neuilly
14 December 1969: Inauguration of the Regional Metro following the start-up of service at the Nation station, the new terminus for the former Vincennes line
19 January 1970: Service starts up on the Étoile – La Défense segment
23 November 1971: Eastward extension from Étoile to Auber
1 October 1972: Westward extension from La Défense to Saint-Germain-en-Laye, by connecting with the former Paris – Saint-Germain-en-Laye line
1 October 1973: Opening of the Nanterre – Préfecture station
8 December 1977: The Regional Metro is renamed the RER A following the inauguration of the central Auber – Nation trunk, connecting service with the former Sceaux line – which became the RER B with the opening of the Châtelet-les-Halles station – and the opening of the Vincennes segment to Noisy-le-Grand – Mont d’Est
19 December 1980: Eastward extension from Noisy-le-Grand to Torcy
29 May 1988: Inauguration of the western interconnection with the opening of the Cergy branch
29 May 1989: Opening of the Poissy branch
1 April 1992: Eastward extension from Torcy to Marne-la-Vallée – Chessy
29 August 1994: Westward extension from Cergy – Saint-Christophe to Cergy – Le Haut
6 June 1997: Start-up of the first double-decker trains, the MI 2N
14 June 2001: Opening of the Serris-Montévrain – Val d’Europe station
26 April 2006: Start-up of the first renovated MS 61
April 2009: Order placed for the first 60 units of the MI 09, a modernised version of the MI 2N
8 February 2011: Presentation of the first MI 09
9 February 2011: STIF launches the elaboration of a masterplan for the RER A
5 December 2011: Start-up of service for the MI 09
6 June 2012: STIF approves the masterplan for the RER A
29 June 2012: Order placed for the last 70 units of the MI 09
25 July 2015: Track replacement work begins