Line 18: Orly – Antony – Massy – Saint Quentin en Yvelines – Versailles
The BELWAY alternative would consist in a dedicated lane on pylons above the existing highways (A86, A12, etc.)
- Orly-Antony with a takeover of all ORLYVAL tracks, one of the first automatic light metro in the world
- Orly-Massy Palaiseau with a dedicated lane on pylons above the A10 motorway
- Massy-Orsay above the A10 motorway
- Orsay-Saclay-Vélizy above the N118 expressway
- Vélizy-Versailles above the A86, then N12 highways
- Versailles-Saint Quentin-en-Yvelines with Satory loop, above the N12 then N10 highways
- And an Antony-Vélizy section above the A86 motorway.
Without viaduct through the countryside, nor expensive tunnel.
For around 58 km-length, or 65 km with local loops, around 1,000 autonomous shuttles would be needed for the capacity requested.
The overall budget would be €2 billion less than the metro version and it would be partly financed by a road toll.
More efficient than the metro, Versailles – Orly would take less than 15 min instead of 30 min with the future metro while decongesting the motorways.
Moreover, an extension would be possible from Vélizy to Boulogne, above the N118 highway, which would connect Boulogne to Orly in less than 15 minutes. The cost would be similar to a cable-car project with a seamless direct journey.