A pragmatic proposal for an Aix-Marseille commuter rail network by 2040

Following personal reflection on the lack of heavy transit in the Aix-Marseille region, I designed a prospective study for the deployment of an ambitious RER (Regional Express Network).

This project stands out for its pragmatism: it does not require the construction of hundreds of kilometers of new tracks, but relies on the optimization and reactivation of existing infrastructure (Aubagne to La Barque line, Rognac to Aix-en-Provence line, Gardanne to Carnoules line...). Civil engineering interventions are targeted at bottlenecks (Saint-Charles underground station, flyovers at Gardanne and La Barque) and on the creation of new stations to serve business parks and dense neighborhoods currently forgotten by the rail network.

I believe that the official "SERM" projects, particularly the Marseille one, severely lack ambition and will not effectively decarbonize transport or reduce car dominance.

Frequencies will also need to be reviewed more generally, especially in the evening, particularly on routes that are attractive at night (such as Aix-Marseille).

This project was entirely realized in August over the span of a few days, with a few small adjustments made in December.

Presentation of the Aix-Marseille RER 2040 Project

Vision and goal

The objective is to transform a hub-and-spoke network centered on Marseille into a true mesh network with numerous transversal connections. The project rests on three pillars:

1. Through-running operations (Diametralization): The end of mandatory terminuses at Saint-Charles thanks to an underground station, allowing for through-lines (e.g., Arles - Toulon). This underground station will be built regardless as part of the LNPCA (New Provence Côte d'Azur Line) project.
2. Reactivation: The reopening of freight or abandoned lines to passenger traffic (Valdonne, Rognac-Aix).
3. Fine-grained coverage: The creation of new stations (La Calade, Grand Littoral, Rousset Z.I, La Duranne...) to reach users where they live and work.

For the project to be effective, however, track doubling and electrification would be needed almost everywhere, as well as effective timetabling similar to the Île-de-France RER. Unified pricing and a dense public transport network connecting residential areas, leisure spots, and workplaces to stations would allow the project to succeed. Without this, the project would never achieve the expected efficiency.

This project, which would accelerate the region's economy and help erase social inequalities, particularly transport-related ones due to the immense cost of car ownership for impoverished households, aligns with my renewed Marseille metro project.

Lines overview

The terminuses in parentheses allow for partial services. Indeed, full connections would only be made at a rate of one train per hour. Partial connections would also allow for local (stopping) services.

Focus: new stations and infrastructure

To make the train attractive, the network must serve new centers of life. This project includes the creation of strategic stations on existing lines:

By city

Marseille

Aix-en-Provence

Venelles

Rousset

Carnoux-en-Provence

La Ciotat

Marignane

Gignac-la-Nerthe

Châteauneuf-les-Martigues

La Mède

Line by line

Line A: Coastal RER - industries (Red)

A busy line, it has more branches than the others. It ensures the link Arles / Cavaillon (Miramas, L'Estaque, Saint-Charles) <-> Toulon (Saint-Charles, Aubagne, La Ciotat-Ceyreste) via the Airport and Marseille.

• Infrastructure: Passage in a tunnel under Saint-Charles to avoid reversal.
• Partial connections: Some local (omnibus) connections have partial terminuses, such as Saint-Charles or Miramas.
• New features: Service to new Marseille stations (Saint-Louis, Grand Littoral, La Calade) for a "metro-like" grid in the Phocaean city.
• Distant connections: Efficient service to Arles, Cavaillon, and Toulon.
• Important Hubs: Miramas, Saint-Charles, l'Estaque, Aubagne.

Line B: Metropolitan RER (Blue)

It connects Aix-en-Provence to Marseille. This important north-south line has two terminuses:

1. A branch towards Saint-Charles (historic).
2. A new branch towards La Capelette via La Blancarde, using existing connecting tracks to serve East Marseille without passing through the hyper-center.

This line would feature numerous express trains to effectively connect the metropolis's two most important cities. Nevertheless, building new tracks (for example, by reusing the A51 highway) would allow for improved travel times, which are currently longer than by road or the "Line 50" coach.

Line C: Arc Valley RER (Yellow)

Symbol of the metropolitan rail renewal, it would connect Saint-Maximin and Trets to major hubs. The Arc Valley is fast growing, with numerous business parks and residential areas, but is currently poorly served by public transport, especially Saint-Maximin which is situated outside the Aix-Marseille metropolis.

• It serves the new Rousset – Business Park station.
• At Gardanne, a newly created flyover allows trains to insert without shearing (crossing conflict) either towards Aix or Marseille, offering high frequency.
• Two new stations: at Luynes and Pont de l'Arc (at the Pauliane campus level) allow for efficient service of the greater South Aix area.

Line D: Étoile / Eastern RER (Green)

Transversal line connecting Trets to Aubagne and La Ciotat, three cities which lie East of Marseille, which have little to no transit connecting them altogether. It reuses the old track between La Barque and Aubagne. It allows hinterland inhabitants to reach employment zones in Aubagne and the coast without transiting through Marseille, decongesting the A52 and offering an alternative to the road in a hyper-dependent zone where connections between towns are sometimes non-existent. This line could potentially be operated with tram-trains and feature a connection with the Aubagne tramway, given the Valtram project which reuses the Valdonne line up to La Bouilladisse.

Line E: North metropolis RER (Purple)

This RER provides efficient service to the West and North of the Pays d'Aix, bypassing Marseille to connect the West (Étang de Berre) to the North-East (Luberon) via the center of Aix-en-Provence.

It has 4 branches, 2 at each end:

• Cavaillon, via the Avignon to Miramas line
• La Mède, via the Pas-des-Lanciers to Martigues line
• Cavaillon, via the Cheval-Blanc line
• Manosque, via the Gap line

Connections with all lines, except D (which essentially duplicates RER F in its entirety), are available on the line. Aix-en-Provence station would be the true nerve center of the line.

Line F: Trans-metropolis RER (Pink)

It would be a rapid line with an interurban vocation connecting Aix-en-Provence to Toulon. Its existence is made possible by the creation of a direct connection (shunt) at La Barque station, allowing trains to pass directly towards Aubagne. It offers a competitive alternative to the car for home-work commutes between Aix-en-Provence and the East of the Metropolis and its Toulon periphery.