On 10 April 2025, the Board of Directors of Île-de-France Mobilités approved the purchase of 96 additional RER Nouvelle Génération (NG) trainsets made by Alstom to continue the replacement of older rolling stock on the RER D.
Expansion of RER NG deployment on Line D
This order follows earlier contracts covering 130 trainsets for RER line E and 36 for line D. The latest batch will bring the total number of RER NG trains assigned to the RER D to 132 units by 2029. The rollout started on the Corbeil-Essonnes branch in December 2024, where around ten units are currently in operation.
The RER NG units are replacing the ageing Z2N fleet on most of the RER D line, except for the Malesherbes branch, which remains operated by Regio 2N trains. The current contract aims to consolidate the transition by increasing the number of RER NG trainsets in service and supporting maintenance readiness through associated infrastructure projects.
Maintenance centres and delivery timeline
Deliveries will be managed jointly by SNCF Voyageurs (Transilien) and Alstom. The region has requested both to align schedules to ensure compliance with commissioning milestones and submit regular progress updates. Subject to delivery timelines being met, about 30 RER NG units are expected to be operating on the RER D by the end of 2025.
Maintenance for the expanding RER NG fleet will be conducted at the Joncherolles Technical Centre, which is currently undergoing refurbishment, and at the new Villeneuve-Saint-Georges facility. The construction of the latter began in June 2024.
Technical and passenger-focused design features
The RER NG is designed as a full-length open train to allow better passenger circulation and is equipped with level boarding and dedicated areas for passengers with reduced mobility. Each unit is outfitted with real-time passenger information systems, adaptive lighting, USB ports, and HVAC systems. Future deployment of the NExTEO train management system is expected to contribute to operational reliability and punctuality.
Île-de-France Mobilités has tied the train procurement to punctuality targets. Between 2023 and 2024, punctuality on RER D improved by one percentage point, reaching 87.5% in 2024. The additional units are intended to support further improvement in operational metrics and overall service consistency.
