6 and 13. From 1992 to 2004, traffic grew by 0.5%, the 11th (of 13) strongest in terms of traffic growth (excluding Line 14, completed in 1998). The busiest stations are Saint-Lazare (34.53 million) and Montparnasse – Bienvenüe (29.46 million), both of which serve multiple lines. In 1998, average weekday traffic reached, commuters, on Saturday and on Sunday. Safety record There have been two accidents on the line: On 23 April 1930, a collision was caused by human error close to the Porte de Versailles station. A train moving north was stopped before a red signal between Porte de Versailles and Convention stations. A second hit it hard from behind, the driver having passed two stop signals at full speed. Two people were killed, and there were numerous injuries. A derailment on 30 August 2000. The train's automatic control function was broken, and the driver was unused to driving manually and arrived too fast into the steep decline before Notre-Dame-de-Lorette station. The derailment turned the car upside-down, and 24 people were injured. The investigation concluded that a specific emergency signal be installed on the approach to the station, and that drivers preserve their skills by not habitually driving with the auto-pilot function. Future Northern extension An extension north to the provisionally named Proudhon-Gardinoux station on the boundary between Saint-Denis and Aubervilliers opened in 2012. The station will serve La Plaine Saint-Denis, a diverse district that includes many television studios. Initially called "Proudhon – Gardinoux" in the planning stages of the project (after the intersection of rue Proudhon and rue des Gardinoux), the name of the new station will be Front Populaire after the adjacent well-known square. Construction began in the second half of 2007, and the tunnel boring machine started to operate in 2009. The tunnel will be dug as far as Aubervilliers, but the entrances to the Pont de Stains and Mairie d'Aubervilliers stations will not be built until later. Works on the first stage cost 198.5 million euros (48% from regional funding, 27.5% from the state, 8.5% from the Department's General Council, 16% from the RATP – on a loan approved by the region). In a second phase, two further stations, at Aimé Césaire and Mairie d'Aubervilliers, opened on 31 May 2022. The final plan sees the extension running all the way to RER B at La Courneuve, where the SDRIF plans an ultimate terminus at the tramway