With a maximum speed of 300 kilometres per hour (190 mph), the line appreciably shortened rail journeys between Paris and Lille.

Its extensions to the north (Belgium, the Channel Tunnel) and the south (via the LGV Interconnexion Est) have reduced journey times to Great Britain and Benelux and for inter-regional trips between the Nord (Pas de Calais) region and the southeast and southwest of France.

At Vémars, the LGV Interconnexion Est joins it via a triangular junction, leading to Charles de Gaulle Airport and Marne-la-Vallée-Chessy; this enables direct trains from London and Amsterdam to Disneyland Paris, as well as the southern destinations (Lyon, Avignon and Marseille) After passing east of the forest of Ermenonville over the viaduc de Verberie, it joins the A1 around Chevrières and accompanies it to the Lille suburbs.

At Fretin, a triangular junction links the LGV to the Lille-Brussels HSL 1 high-speed line eastwards, crossing the border at Wannehain and joining the conventional network at Lembeek, south of Brussels.

The LGV Picardie project would address this issue by serving Amiens, and would reduce the Paris–London journey time to less than 2 hours.

The foreseen opening of the Channel Tunnel made it a project of the utmost urgency, leading to an acceleration of work.

[3] Deutsche Bahn hope to run an ICE 3 train through the Channel Tunnel on 19 October 2010,[4][5] in preparation for possible future operations.

[7] In September 2008, Air France-KLM indicated a desire to take advantage of the change in the law and apply to run rail services.

This led to Veolia looking for new partners, with the announcement that it would begin working on new proposals in cooperation with Trenitalia to run services from Paris to Strasbourg, London and Brussels.