Preliminary design was completed in June on the 33km southern section of the orbital Red Line. Red Line South will run from Pont de Sévres in the west to serve Châtillon-Montrouge, Villejuif, and Créteil before terminating at Noisy-Champs. The line will have 16 stations, all of which will interchange with light rail, metro or RER lines.

The line will serve 22 municipalities and will have a massive impact on journey times between the suburbs. For example Issy RER – Champigny Centre will fall from 1h 26min to just 27 minutes.

The journey time between the two termini will be around 35 minutes, compared with 1h 05 at present, and trains will run at an average speed of 55-60km/h. Services will operate at 3-4 minute intervals at peak times, and trains will be 120m long, accommodating at least 1000 passengers.

Twenty-one public meetings will be held in the municipalities along the route of the proposed line between September 13 and November 15. Preliminary construction is expected to start by the end of 2013, and the line is due to be commissioned in late-2018.