Established in its unified structure in 2015 (succeeding Réseau Ferré de France [RFF] and reintegrating SNCF Infra) and transformed into a state-owned public limited company (Société Anonyme) in 2020 under the French Railway Reform Act, SNCF Réseau is the sole national rail infrastructure manager of France. Headquartered in Saint-Denis (Paris), SNCF Réseau is a core pillar of the state-owned SNCF Group, employing over 50,000 engineers, technicians, traffic controllers, and track maintenance specialists.

SNCF Réseau is responsible for maintaining, modernizing, and operating approximately 28,000 kilometers of active rail lines, of which over 2,800 kilometers are dedicated high-speed lines (Lignes à Grande Vitesse – LGV) and more than 16,000 kilometers are electrified. It controls timetable path allocation, network access pricing, and real-time signaling for dozens of licensed passenger and freight railway undertakings operating under European open-access regulations.

The organization leads multi-billion-euro renewal and digital railway modernization schemes across France. Key infrastructure initiatives include the nationwide deployment of the European Rail Traffic Management System (ERTMS / ETCS Level 2) on the high-density Paris–Lyon high-speed line, the rollout of centralized network control towers (Commande Centralisée du Réseau – CCR), the regeneration of regional feeder lines, and the construction of the cross-border Lyon–Turin base tunnel rail link. Through its subsidiary SNCF Gares & Connexions, it oversees the development and station operations of roughly 3,000 passenger stations nationwide.