Project Profile: T1 Western Extension, Greater Paris

The T1 Western Extension project is a critical 6.4 km light rail development enhancing mobility in the dense western suburbs of Greater Paris. Commissioned in 2024, this two-phase expansion integrates the communes of Asnières-sur-Seine, Bois-Colombes, and Colombes into the regional transit network, connecting with the Transilien J and T2 lines. This profile details the technical specifications, strategic importance, and key stakeholders of this vital infrastructure upgrade.

Technical Specifications

The T1 Western Extension is engineered as a mixed-traffic urban tramway, designed to coexist with vehicular, bicycle, and pedestrian flow. The route alignment required extensive preparatory work, including the relocation of subterranean utilities and complete pavement reconstruction. A key technical feature is the 500-meter shared track section with the T2 tramway line near Parc Pierre Lagravère, an innovative solution to optimize land use and reduce operational complexity.

Infrastructure development included the installation of modern platforms, tracks, and overhead power lines. Station design incorporates durable granite-type coatings and Marc Aurel street furniture to enhance passenger experience and public space aesthetics. A major engineering challenge was the complete redevelopment of Les Courtilles station, which was expanded to accommodate three trams simultaneously, thereby increasing line capacity and passenger throughput. The project is supported by the La Marine maintenance facility in Colombes, which is shared with the T2 line, reflecting a collaborative and cost-efficient approach to asset management.

Key Takeaways

• Strategic Network Integration: The extension provides a crucial link between previously underserved residential zones and major employment centers, seamlessly connecting with the Transilien J suburban rail and the T2 tramway to create a more resilient and interconnected regional network.
• Collaborative Funding Model: The project’s €225 million budget was secured through a robust partnership between the French State (€32M), the Île-de-France Regional Council (€75M), and the Hauts-de-Seine General Council (€45M), demonstrating a successful multi-level governance approach to funding critical infrastructure.
• Significant Socio-Economic Impact: By serving over 200,000 residents and projecting the creation of 70,000 jobs, the line is a powerful engine for economic development and social equity, drastically reducing travel times and improving access to essential services for communities in western Paris.

Frequently Asked Questions (FAQ)

When did the T1 Western Extension open?

The final phase of the T1 Western Extension became fully operational in 2024, completing the 6.4-kilometer route connecting Les Courtilles in Asnières-sur-Seine to Gabriel Péri in Colombes.

Who built the T1 tram extension in Paris?

The T1 Western Extension was a collaborative project led by RATP, the Parisian public transport operator, which managed construction and maintenance. Systems engineering was managed by Systra, and the project was financed by multiple public bodies, including the French State, the Île-de-France region, and the transport authority Île-de-France Mobilités (IDFM).