it’s one of these baffling French regional buses. It appears to be operated by Zou Lignes Express Régionales - which is effectively the regional public transport operator I think.

I can’t find any information about passes or reservations on their website, but that doesn’t mean it’s not accepted!

 https://zou.maregionsud.fr/en/

thanks for the quick reply and looking into this topic. So I guess I will just try it, otherwise the bus is not too expensive.

Did you try this @Trainmike? Does anybody else have any info?

I might be on this bus myself next month, to get from Briançon to Paris. There are no sleepers running on my date, and the direct TGV from Oulx is still part-replaced by a bus. So it looks like a bus to St Michel Valloire or St Jean de Maurienne Arvan to pick up a TGV to Paris is the best option.

It’s actually not much less convenient, and could be cheaper vs the reservation cost from Oulx-Paris.

Hey @ralderton! Yep, I took the bus two weeks ago and it worked. Although nobody could help me if it is valid or not ( asked at SNCF, the Bus Carrier and Interrail). The bus driver looked at my mobile Interrail ticket and understood it to be an SNCF ticket. So I didn't need to make a reservation or pay anything extra.

That's often how it works. The timetable data somehow claims you need a reservation for many of these buses, but AFAIK such reservations don't exist. I often just say to the driver that it's an SNCF ticket, when showing my QR code, and that usually works.

My rule of thumb is that when the SNCF TER website of the region mentions the bus (often as "Car TER"), then train tickets (and thus Interrail/Eurail) are valid. Although in this case, it's a bit fuzzy: you can find some buses on www.sncf-connect.com but not in the "fiches horaire” or the TER network maps on the TER websites of both regions involved.