Originally designed as turbotrains to be powered by gas turbines, TGV prototypes evolved into electric trains with the 1973 oil crisis.

The success of the first high-speed service led to a rapid development of lignes à grande vitesse (LGVs, 'high-speed lines') to the south (Rhône-Alpes, Méditerranée, Nîmes–Montpellier), west (Atlantique, Bretagne-Pays de la Loire, Sud Europe Atlantique), north (Nord, Interconnexion Est) and east (Rhin-Rhône, Est).

[3] In 2007, the world's fastest scheduled rail journey was a start-to-stop average speed of 279.4 km/h (173.6 mph) between the Gare de Champagne-Ardenne and Gare de Lorraine on the LGV Est,[4][5] not surpassed until the 2013 reported average of 283.7 km/h (176.3 mph) express service on the Shijiazhuang to Zhengzhou segment of China's Shijiazhuang–Wuhan high-speed railway.

[6] During the engineering phase, the transmission voie-machine (TVM) cab-signalling technology was developed, as drivers would not be able to see signals along the track-side when trains reach full speed.

Brest, Chambéry, Nice, Toulouse and Biarritz are reachable by TGVs running on a mix of LGVs and modernised lines.

At the time the Government of France favoured new technology, exploring the production of hovercraft and the Aérotrain air-cushion vehicle.

It was articulated, comprising two adjacent carriages sharing a bogie, allowing free yet controlled motion with respect to one another.

The first electric prototype, nicknamed Zébulon, was completed in 1974, testing features such as innovative body mounting of motors, pantographs, suspension and braking.

Body mounting of motors allowed over 3 tonnes to be eliminated from the power cars and greatly reduced the unsprung weight.

After two pre-production trainsets (nicknamed Patrick and Sophie) had been tested and substantially modified, the first production version was delivered on 25 April 1980.

[13] This commitment to a democratised TGV service was enhanced in the Mitterrand era with the promotional slogan "Progress means nothing unless it is shared by all".

[15] The TGV (1981) was the world's second commercial and the fastest standard gauge high-speed train service,[16] after Japan's Shinkansen, which connected Tokyo and Osaka from 1 October 1964.

On 3 April 2007 a modified TGV POS train reached 574.8 km/h (357.2 mph) under test conditions on the LGV Est between Paris and Strasbourg.

[4][5] This record was surpassed on 26 December 2009 by the new Wuhan–Guangzhou high-speed railway[19] in China where the fastest scheduled train covered 922 km (573 mi) at an average speed of 312.54 km/h (194.20 mph).

V150 was a specially modified five-car double-deck trainset that reached 574.8 km/h (357.2 mph) under controlled conditions on a test run.

All TGVs are at least bi-current, which means that they can operate at 25 kV 50 Hz AC (used on LGVs) and 1,500 V DC (used on traditional lines).

Trains travelling internationally must accommodate other voltages (15 kV  16.7 Hz AC or 3,000 V DC), requiring tri-current and quad-current TGVs.

When passing between areas with different electric systems (identified by marker boards), trains enter a phase break zone.

Once the train exits the phase break zone and detects the correct electric supply, a dashboard indicator illuminates, and the operator can once again engage the motors.

There were seven bi-current half-sets without seats that carried mail for La Poste between Paris, Lyon and Provence, in a distinctive yellow livery until they were phased out in 2015.

Owing to early complaints of uncomfortable pressure changes when entering tunnels at high speed on the LGV Atlantique, the Réseau sets are now pressure-sealed.

The series was commissioned from December 2011 for links to Germany and Switzerland (tri-current trains) and to cope with the increased traffic due to the opening of the LGV Rhine-Rhone.

The design that emerged from the process was named TGV M, and in July 2018 SNCF ordered 100 trainsets with deliveries expected to begin in 2024.

The development of TGV trains is being pursued in the form of the Automotrice à grande vitesse (AGV) high-speed multiple unit with motors under each carriage.

[39] In June 2021, there were approximately 2,800 km (1,740 mi) of Lignes à Grande Vitesse (LGV), with four additional line sections under construction.

In over four decades of operation, the TGV has not recorded a single passenger fatality in an accident on normal, high-speed service.

[citation needed] The concerns put forward by the protesters centre on storage of dangerous materials mined during tunnel boring, like asbestos and perhaps uranium, in the open air.

In addition to the concerns of the residents, RFB – a ten-year-old national movement – opposes the development of Italy's TAV high-speed rail network as a whole.

Although the train moves at high speed, it accelerates and decelerates smoothly, allowing for medical procedures to be performed during transport.

The name inOui was chosen because it sounds like the French word inouï meaning "extraordinary" (or more literally, "unheard of").