Understand
Frequently asked questions
Timetables, prices, split tickets, CO₂, delays, personal data: the short answers.
Where do the timetables come from?
From timetables published as open data by the transport networks themselves, gathered on transport.data.gouv.fr. Journeys are calculated by MOTIS, a free journey-planning engine installed on our servers.
The full list is on the Sources and licences page.
Are the prices shown exact?
It depends on the journey, and one-go always says so. A price is either an exact price, published by the network with its timetables, or an estimate, always preceded by the “≈” sign.
An estimate is never presented as an exact price. Before buying, check the price on the operator's website.
The details are on the How it works page.
Why an estimate for TGV and OUIGO trains?
The price of a TGV INOUI or OUIGO train changes with the day, the time and how full the train is. one-go does not have that day's price: it shows an estimate, marked with “≈”, based on the distance.
The “Buy the ticket” link takes you to the operator's website, where you will find the exact price for your date.
What are split tickets, and what are the risks?
It means buying two tickets, one for each part of the journey, instead of a single end-to-end ticket. The total can be cheaper.
The risk: since 7 June 2023 (European Regulation 2021/782), tickets bought separately are separate contracts. If the first train is late, the connection is not guaranteed.
Everything is explained on the Split tickets page.
How is CO₂ calculated?
For each leg, one-go multiplies the distance travelled by an emission factor specific to the mode of transport (train, coach, bus, metro…). The factors are orders of magnitude published by ADEME, the French environment agency.
The result is compared with the same journey made alone in a petrol or diesel car.
The factors are detailed on the How it works page.
Are delays taken into account?
Yes, when the network publishes its real-time information as open data. The delay is then shown on the journey (“+3 min”), and a cancelled train is flagged.
Not all networks publish this information. Without it, one-go shows the scheduled times.
Can I book on one-go?
No. one-go does not sell tickets: it is an information service. For each journey, a link takes you to the operator's website, where you will find the exact price and can buy your ticket.
What do you do with my searches?
Only what is strictly needed to answer you. The places you enter are sent to the services that calculate the journey, for the duration of the request. A technical cache keeps them for 24 hours at most. No profile is created, nothing is sold.
Audience measurement, anonymous and cookie-free, never keeps a place or a location.
The details are on the Privacy page.
A journey or a stop is missing: what can I do?
Sometimes a network does not publish its timetables as open data yet, or a file is incomplete.
Write to us, choosing the subject “Report a journey error”, with the departure, the arrival and the line concerned.
Didn't find your answer? Write to us.