RER NG train deployment has passed another milestone in Île-de-France: the 100th double-deck unit built by Alstom entered passenger service on 21 May. It made its first journey from Chelles-Gournay station, giving fresh momentum to the modernisation of regional rail transport in the Paris region.

RER NG train: Paris fleet renewal gains pace
RER NG train: Paris fleet renewal gains pace

The RER NG programme goes beyond a straightforward fleet replacement. It sits within a wider effort to improve daily mobility on some of Île-de-France’s busiest rail corridors, where capacity, punctuality and passenger comfort remain key issues for operators and transport authorities.

RER NG train rollout expands on lines D and E

RER NG, short for Nouvelle Génération, is the fourth generation of rolling stock developed for the RER network. The trains have been running on the RER E line since November 2023, and services on the RER D line began in December 2024. In its official update on the RER D launch, Alstom described RER NG as double-deck rolling stock designed for lines D and E of the Île-de-France Mobilités network.

The RER NG double-deck train brings better reliability, improved accessibility and a more comfortable onboard environment than earlier generations. That matters on lines D and E, where heavy passenger flows require rolling stock suitable for intensive regional operation.

Île-de-France Mobilités has financed and ordered 262 RER NG trainsets in total. The programme covers 132 seven-car trains for the RER D line, each 130 metres long, along with 130 shorter trainsets for the RER E line, each measuring 112 metres. The full investment stands at €5.5 billion and is funded entirely by Île-de-France Mobilités.

Île-de-France Mobilités backs wider fleet renewal

The latest order was placed by SNCF Voyageurs in June 2025. It covers another 96 RER NG trainsets for the RER D line, strengthening the role of the new fleet in the long-term renewal of regional rail transport. Alstom’s official announcement of the 96-train order also confirms the total of 262 RER NG trainsets ordered for lines D and E.

Since 2016, Île-de-France Mobilités has put major investment into replacing and modernising its rolling stock. More than 1,550 new or refurbished metros, trains, RER units and trams are already in service across the wider Paris region. Within that larger programme, the RER NG fleet is one of the most visible renewal projects.

The deployment on lines D and E involves Île-de-France Mobilités, SNCF Voyageurs and Alstom. Their work is focused on reshaping regional mobility by addressing the operational limits of older rolling stock and improving conditions for passengers on two heavily used RER lines.

Alstom RER NG trainsets raise capacity and comfort

The new RER NG trainsets raise capacity by up to 20%, helping the network meet growing passenger demand. They also improve the travel experience with air conditioning, passenger information systems, enhanced connectivity and upgraded lighting.

The first RER NG trains entered service on RER E in 2023. Operation on RER D followed in 2024, and the 100th train now underlines the continued expansion of the fleet. Railway Supply previously covered Alstom’s RER NG fleet expansion in Paris, reflecting the broader procurement context behind the current rollout. For Île-de-France, the programme remains a practical step toward more reliable, accessible and comfortable regional rail services.