Île-de-France tramway Line 13 Express

Île-de-France tramway Line 13 Express (T13 Express; French: Ligne 13 Express du tramway d'Île-de-France, known as the Tangentielle Ouest and Tram Express Ouest in the planning phase) is a suburban tram-train line in Yvelines, west of Paris, which opened on 6 July 2022. The line is operated by Transkeo T12-T13, a joint venture 51% owned by Keolis and 49% by SNCF Voyageurs.

Route
The line is 19 km long. It connects the communes of Saint-Germain-en-Laye (north) and Saint-Cyr-l'École (south), in the western outer suburbs of Paris. It has interchanges with existing SNCF Transilien lines L, N and U, as well as Réseau Express Régional (RER) lines A and C.

Project
The line replaced a former branch of Transilien Line L between Saint-Germain-en-Laye–Grande-Ceinture station and Noisy-le-Roi station, going further north to Saint-Germain-en-Laye station and further south to Saint-Cyr station.

Alstom Citadis Dualis tram-trains are used on the line.