Which French train design is known for having two passenger decks?

TGV Duplex is the French train design known for having two passenger decks.

The TGV Duplex is a double-deck version of France’s TGV high-speed train. Its two-level carriages increase seating capacity without requiring longer trains or additional platform space, making the design especially useful on busy routes radiating from Paris.

The first Duplex trains entered service in the 1990s. They were developed for France’s expanding high-speed network and became a recognizable part of long-distance services on lines such as the LGV Sud-Est and LGV Méditerranée.

“Duplex” describes the train’s two passenger levels, not a two-train service. The power cars at each end remain single-level vehicles, while the passenger trailers provide the double-deck seating arrangement. TGV Duplex trains have also influenced later high-capacity European train designs.