Avelia Horizon is a high-speed, double-deck trainset developed by French rolling stock manufacturer Alstom.
The trainsets are part of Alstom’s Avelia family of high-speed trains. According to the company, Avelia Horizon is currently the only double-deck high-speed train available worldwide.
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The project originated from a French National Railway Company (SNCF) programme to procure a new generation of high-speed trains.
The development of the trainset progressed under the name of TGV M. It was rebranded by SNCF as TGV INOUI in 2025 for operation on the French national network.
Testing of the Avelia Horizon trainset on the French national network began in 2023 to validate performance and safety for certification.
Commercial services are planned to start in 2026, with initial operations to begin on the Paris–Lyon–Marseille corridor.
SNCF plans a phased deployment of Avelia Horizon across the French high-speed network over a ten-year period following the initial launch.
Avelia Horizon specifications
The Avelia Horizon features a pair of shortened, high-performance power cars, together with double-deck passenger cars.
The high-speed trainset can be configured in multiple train lengths and interior layouts. This will enable operators to add or remove passenger cars in response to demand or operational needs.
The trainset adopts an articulated architecture rather than a conventional arrangement to lower operating costs while improving ride stability and reducing noise and vibration.
It also uses fewer bogies, which reduces around 30% in preventive maintenance costs.
In its 200m highest capacity configuration, Avelia Horizon high-speed trains can accommodate up to 740 passengers. Passenger capacity can exceed 1,000 passengers in multiple-unit configuration.
The maximum operating speed of the trainset is 320km/h.
Alstom has also made improvements to the traction system and its ability to return energy to the catenary during braking.
Eco-driving measures reduce energy consumption per seat by about 30% compared with comparable high-speed trains, according to the company.
Furthermore, improvements in aerodynamics and a more efficient traction system are expected to deliver approximately 20% lower energy use than existing TGVs, according to SNCF.
Avelia Horizon design details
Avelia Horizon’s exterior design focuses on aerodynamic efficiency, including optimised nose shaping and minimised surface cavities to reduce resistance to motion.
Interior features of the trains include enlarged windows to improve external visibility. The layout of trains prioritises effective light management and digital connectivity for passengers.
Materials and forms in passenger areas are specified to support a consistent and comfortable travel environment.
The trains are also equipped with WiFi, individual power sockets, and USB ports.
Accessibility features include wide doors aligned with European platform heights for step-free boarding.
The train provides real-time passenger information, while a remote diagnostic system supports predictive maintenance to improve reliability and availability.
In November 2021, Avelia Horizon was recognised with the German Design Award by the German Design Council (Rat für Formgebung) and the German Federal Ministry for Economic Affairs and Energy.
Orders and deliveries
In July 2018, SNCF Mobilités approved a firm order for 100 Avelia Horizon trains under a contract valued at €2.7bn ($3.16bn) (before firming).
SNCF placed an €590m ($600m) order for an additional 15 Avelia Horizon trains in August 2022. The order represented the second optional tranche under the Avelia Horizon innovation partnership framework between SNCF and Alstom.
In October 2025, Eurostar placed an order for 30 Avelia Horizon trains for €1.4bn ($1.62bn), with options for 20 additional trains, which could increase the value of the contract to €2bn ($2.32bn).
The order represents the third tranche of the framework contract between SNCF and Alstom, of which Eurostar is a beneficiary.
The trains will be operated by Eurostar under the name Eurostar Celestia across five countries, including Germany, Belgium, France, the Netherlands and the UK through the Channel Tunnel. The first trains are expected to be delivered in January 2031 and enter service in May 2031.
In October 2024, Alstom agreed to supply 12 Avelia Horizon trainsets to Proxima, an independent operator planning to enter the French high-speed market. The €850m ($940m) agreement includes 15 years of maintenance for services on Atlantic coast routes.
The first trainsets are expected to be delivered in 2028 and will be deployed across Proxima’s planned network, across Bordeaux, Nantes, Rennes, Angers, and Paris.
In March 2025, Morocco’s national railway operator ONCF signed a €781m ($842m) contract for 18 Avelia Horizon very high-speed trains to reduce travel times on the Tangier-Marrakech corridor.
Alstom’s Avelia high-speed train variants
Alstom’s Avelia high-speed train range includes Avelia Stream and the Avelia Liberty models.
Avelia Stream is a family of single-deck high-speed trains designed for a wide range of applications. These models can operate at speeds ranging from 200km/h to 300km/h.
Avelia Liberty is designed for Amtrak’s NextGen Acela II for the US Northeast Corridor. It can reach a speed of up to 300km/h.