
“Tangentielle West” is a tram-train project in the Yvelines department. In a first phase, it will extend the “Grande Ceinture West” railway line around Paris northwards to the RER express railway station in Saint-Germain, and southwards to the RER station in Saint-Cyr. In a second phase, it will extend the line northwards between the Grande Ceinture at Saint-Germain and the RER station at Achères Ville, passing through Saint-
Germain-en-Laye, Poissy and Achères on urban sections and the national rail network over about 10.6 km.
Tangentielle West will boost public transport from north to south in the Yvelines department, providing numerous connections (RER lines A and
C, and Transilien regional train lines L , U and N), and facilitating travel between people’s homes and places of work.