The work

The latest work news

Updated on 2026 February 24

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Video - Participatory afforestation with kindergarten students

Updated on 2026 February 24

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The Mare aux Bœufs sector is accessible again

Updated on 2026 February 24

railway embankment at the entrance to Poissy

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Preparatory work in the La Bruyère district of Poissy

The main stages of the work

Today

2021-2026

Concession works

Today

2024-2026

Preparatory work

2026-2028

Infrastructure works

2028

Tests and dry runs before commissioning

Work by sector

Perspective of the passage of the Mare aux Boeufs in the forest of Saint-Germain

Forest of Saint-Germain south

Poissy La Bruyère

Poissy av. de Versailles and bd. Gambetta

Poissy boulevard de l'Europe

©Richez Associés - Non-contractual development intention - green wall on rue Adrienne Bolland

Poissy - Saint-Exupéry district

Photo showing the installation of the new Saut-de-Mouton bridge over the tracks of the RER A, line J and the Normandy lines between Poissy and Achères.

Forest of Saint-Germain north

©Richez Associés - Non-contractual development intention - Terminus d'Achères

Achères