In November 2006, Paris transit authorities opened a new tram-train line (T4) running from Aulnay-sous-Bois to Bondy (right side of Seine river), using the tracks of an old life expired suburban railway (Coquetiers Line), with old and noisy rolling stock. Even though the old suburban line had 14 level crossings, it was still important for the connection with Paris center.
The renewal of the line started in 2003 when the rail line was doubled from Livry-Gargan to Aulnay-sous-Bois. The level crossings were protected by a visive signaling system and the aged commuter train rolling stock was replaced with modern dual low floor Siemens Avanto TramTrains, which can run in tramway mode (750 V DC) and in electric train mode (25 KV AC). The new tram-train was a cost effective conversion of an existing railway into a modern tramway, re-using the old commuter railway infrastructure. The commuter train heritage is retained with the TramTrain Line being operated by the SNF (Société Nationale des Chemins de fer français) or National Railways.
Two new extensions are actively being planned for: an intermediate branch from Clichy-sous-Bois to Montfermeil, a northern extension from Aulnay-sous-Bois to ParinorCountryCountry France France.
The cost of TramTrain Line T4 was a mere $11 million/km. to build and illustrates the growing popularity of TramTrain in Europe and now in North America as a cost effective alternative to more expensive construction.
| Country | France |
| Line | T4 (Coquetiers Line) |
| Inhabitants | District 11.175.000 |
| Date opening | 2006 |
| Future development: | northern (Garonor) and eastern (Montfermeil) extensions |
| Length (km) | 8.0 |
| Track sections | on an existing railway (Coquetiers Line) |
| Stops | 10, average distance 890 m |
| Platforms | — |
| Platform doors | — |
| General characteristics | height cm 35 |
| n. of vehicles | 15 |
| n. of cars per vehicle | — |
| Type | steel wheels bi-directional |
| Vehicle dimensions (m) | length 37, width 2.65 |
| Vehicle capacity (pax) | tram: 242 (80 seated) |
| Frequency | 7’/15′ |
| Current/Voltage | 750 V DC overhead/25 KV AC overhead |
| Type of guide/gauge | standard gauge rails (1435 mm) |
| Speed Km/h | Comm 25, Max 110 |
| Accel./Decel. (m/sec2) | — |
| System capacity | — |
| Ridership | — |
| Total cost | 7 M Euro/km |
| Staff | — |
| System builder | SIEMENS |
| Model | Avanto |
Tags: Abbotsford, C-train, Chilliwack, commuter rail, cost per km, Diesel LRT, Evergreen Line, infrastructure, interurban, Karlsruhe, light rail, LRT, NDP, passenger rail, Patrick Condon, Rail for the Valley, skytrain, streetcars, study, Surrey, track-sharing, tram, trams, tramtrain, Translink, UBC, VALTAC, Vancouver
Rail For The Valley 
October 7, 2009 at 9:54 am
The problem in this region is that there are few abandoned rights of way in the areas where demand for transit is highest. All the most coveted routes for tram-train are owned by the CPR. Even “abandoned” routes are held tightly by the CPR in the hope that some day they can have the land re-zoned and make enormous profits. Gordon Campbell, as a former employee of CPs real estate division, believes that’s what should happen. He’ll never support rail transit on those routes because it would get in the way of CPs ability to profit.
It’s way past time to stop the insanity. The CPR was given huge amounts of real estate as a bribe to extend their main line from Port Moody to the town of Granville (now called Vancouver). What’s particularly insulting to citizens is that the CPR was going to build that extension anyway, without any bribe whatsoever because they realized Port Moody lacked the deep water needed by ocean going ships.