Paris Métro Line 18

Line 18 is the result of the Grand Paris public transport network project, presented by the President of the Republic Nicolas Sarkozy in 2009. This provided for a large gauge green line connecting Orly Airport to Roissy via Saclay and La Défense. The green line is then included in the Grand Paris Express project with a terminus this time fixed at Nanterre, with entry into service then envisaged between 2025 and 2030.

On 6 March 2013, the Prime Minister Jean-Marc Ayrault unveils the map of the future network of the Nouveau Grand Paris (new name of the Grand Paris Express), on which appears for the first time the denomination of "line 18". Its route is then limited to the section Aéroport d'Orly – Versailles-Chantiers, the future of the section to Nanterre becoming uncertain. A variant of the route making it possible to serve the Versailles Saint-Quentin-en-Yvelines University was being considered, but was subsequently abandoned in favor of a more direct route. It is also on this occasion that the choice of a metro with an appropriate gauge is indicated, in view of the expected ridership which does not justify trains as large as on the other lines.

In 2014, Prime Minister Manuel Valls announced that the sections CEA Saint-Aubin – Massy – Palaiseau and Massy – Palaiseau – Aéroport d'Orly would be effective from 2024, the line having to be ready in time to serve the site envisaged for the Universal Exhibition of 2025.[2]

The reinforced consultation on the line 18 project (section Orly Airport – Versailles-Chantiers ) took place from 12 May to 12 June 2015.[3] The public investigation file was sent to the regional prefect by the SGP in the summer of 2015, for an investigation from 21 March to 26 April 2016.[4]

Line 18 is declared of public utility on 28 March 2017.[5]

In January 2018, Prime Minister Édouard Philippe announced the withdrawal of the French candidacy for the organization of the Universal Exhibition of 2025.[6] It was then envisaged that a first section from Massy-Palaiseau to CEA Saint-Aubin be put into service from 2026.[7][8]

On 15 May 2020, the Société du Grand Paris awarded Vinci Construction the first civil engineering contract for the line 18, for an amount of 800 million euros: it concerns the section from Orly to the Saclay plateau.[9][10]

From Monday 15 June to Friday 17 July 2020, an additional public inquiry is carried out, to obtain an amending declaration of public utility, allowing the declaration of public utility to be made compatible with the town planning documents of Orsay, Palaiseau and Wissous.[11]

The State-Region memorandum of understanding having ratified the fact that the line 18, originally called the green line, would be an automatic metro line with suitable gauge.[13][14] the type of rolling stock that will circulate there will be an automatic metro, running on iron. The cars will have a width of approximately 2.50 meters (8 ft 2 in) (a size similar to that of the current Paris metro) and the trains will be composed of three or four cars which can accommodate 350 travelers by train.[15] The trains will be supplied by a third rail in 1500 V, unlike lines 15, 16 and 17.[16]

Many local criticisms have been voiced regarding this project. Thus, residents and elected officials of the municipalities crossed by the aerial metro ask that it be buried.[21][22] In addition, the inhabitants of Wissous, a town located between Antony and Orly Airport, crossed by the line but not served by it, in fact feel forgotten by the project.[23]

The most important criticisms come from expert opinions outside the field of local democracy, pointing out in particular a gap difficult to justify between the dimensioning of this infrastructure and the flows that it would accommodate in view of the tools of territorial analysis and flow simulation. . Indeed, the justification of the line 18 project within the overall public transport network project of Greater Paris presented in 2009–2010 was that of the connection of employment centers among them, which would imply a significant flow between them. However, " connections between job centers in Île-de-France only represent 3% of transport needs ".[24] In addition, the analysis of the socio-economic characteristics of the territories crossed shows that we have in the Orly pole " a high proportion of workers "on the spot", that is to say holding a job. in their commune of residence ", and that in the centers of Massy and Versailles," "trips are much more made internally than to an external basin" ".[24]

Thus, from 2015, the General Investment Commission (CGI) issued an unfavorable opinion for line 18, in its Saclay-Versailles section.[25]

The FNAUT Île-de-France transport users association considers line 18 as

a prestigious metro disconnected from real needs travel.

AUT / FNAUT Île-de-France therefore wishes that an opinion be rendered unfavorable to the public utility of this line}}.[26] In 2017, it renews its criticisms on the oversizing of the line 18 and considers that a tram-type service could be sufficient for the latter.[27]

According to Pascal Auzannet, former senior official in charge of reflections on the Grand Paris metro project within RATP in the 2010s,[28] it would be wiser to extend the 7.3 kilometers from the Orlyval to the Saclay plateau. Indeed, with a transport capacity at peak hour greater than 7500 passengers, this possibility is compatible with the traffic forecasts presented in 2016 during a public inquiry. In an interview with the Public Establishment in charge of the development of the urban project of the Saclay plateau, subsequent to the publication of the book, he generalizes this comment by indicating: “ The choice of a metro (rather than simple buses on specific sites) was therefore fully justified, but was there a need for a heavy metro, as on the other lines, with the risk of overcapacity? Personally, I have always thought that the initial option was oversized. (...) at the beginning, we envisaged capacities of 40,000 passengers in each direction of traffic, while demand by 2030 should not exceed 5–6,000”.[29]

On 22 June 2018, during a conference of "Professional Groups of Arts and Crafts", Jean-Marc Jancovici, speaking of the carbon impact of the various infrastructures, said: “Line 18 […] will never refund its initial carbon, so if we want to do it [this project] on the grounds of carbon, we must not do it".[30]

In July 2018, the Council of State rejected the requests of several communities and associations for the defense of the environment and validated the declaration of public utility.[31]

In July 2020 during the last public inquiry into the project, FNAUT Île-de-France Transport Users Association pointed out in a message posted on the microblogging network Twitter[32] that the socio-economic profitability of this line has been revised upwards in an unexplained manner.

Line 18 will serve several notable points of Île-de-France:

• the Orly Airport;
• the Saclay plateau and its universities;
• the new town of Saint-Quentin-en-Yvelines in the town of Guyancourt;
• the city of Versailles.