A new high-capacity electric bus line, Tzen 4, has entered service in Essonne. The line uses 24-metre bi-articulated electric buses equipped with ground-based rapid charging technology from Alstom.
The route connects Viry-Châtillon and Corbeil-Essonnes and is designed to provide more regular journeys and increased capacity along one of the busiest bus corridors in the outer suburbs of Paris. Daily ridership is estimated at more than 47,000 passengers.
Tzen 4 replaces much of the existing line 4206 (formerly 402), which has experienced crowding and delays due to road congestion. The former service will continue to operate every 15 minutes on weekdays alongside the new line.
The new route runs for around 14 kilometres on largely redesigned infrastructure, with dedicated lanes along much of the corridor to separate buses from general traffic. It serves five municipalities — Corbeil-Essonnes, Évry-Courcouronnes, Ris-Orangis, Grigny and Viry-Châtillon — and includes 30 stations.
The service uses 24-metre bi-articulated electric buses with a capacity of around 140 passengers, compared with about 100 on the previous vehicles. The buses are equipped with ground-based rapid charging technology at selected stops, allowing battery top-ups in a few minutes using the SRS system developed by Alstom.
The buses used on the new Tzen 4 service in Essonne were developed by the Swiss manufacturer Hess, taking over production after the original builder Van Hool went into bankruptcy. They are equipped with high-power batteries supplied by Kiepe Electric.
Stations along the route have been rebuilt with extended platforms, upgraded shelters and real-time passenger information displays. Operating hours run from approximately 05:00 until 01:00, with a target frequency of one bus every five minutes during peak periods.
Construction of the line and associated works represents an investment of about 123 million EUR. Funding has been provided by the Île-de-France Region, the Department of Essonne, the French state and the European Union.
