Carbon footprint

The trip planner provides an estimation of the environmental impact of its calculated trips, in comparison with car use.

CO2 output is estimated on the basis of distances traveled and the average carbon output coefficient of the different modes of transport.

Coefficients used, by transport mode

• High-speed train (T.G.V.): 55.9 gCO2/pass.km 
• Bus : 55.9 gCO2/pass.km 
• Long-distance train (Grande Ligne): 25.16 gCO2/pass.km 

The coefficients for car, bus and tramway come from data gathered by the Agency for Environment and Energy Management (ADEME) in partnership with representatives of the French public transport operators. These coefficients are used by the ADEME eco-calculator (see links below).

The source of the "TGV" and "TER" train's coefficients is the SNCF, that also has its own eco-comparator (see links at bottom of page).

The coefficients used are only averages. In reality, new cars pollute less than older cars and the same holds true for buses, coaches and trains... The carbon footprint information provided by the website can therefore only be considered as an indication of the environmental impact (generally lesser with public transport) - keeping in mind that substantially different results could be obtained for the same route, depending on the models of vehicles and the calculation assumptions used.

The coefficients per transport mode used by the website trip planner may change over time, especially if new reference coefficients are made public by the ADEME or SNCF. This page would then be updated.

To learn even more about the carbon footprint and energy policies:

• ademe.fr website and its eco-calculator/
• SNCF website : Information on CO2 emissions decrypted for you