I went on that line the other day. The odd thing is, it is shown on the SBB map as a railway
I didn't realise it was a tram until I saw it wasn't on the departure boards at Basel SBB. .
The Basel - Rodersdorf line was built as a light railway, the Birsigtalbahn. The Basel - Aesch/Dornach routes were also built as 'railways' (The Birseckbahn). Hence their appearance on the SBB map.
Incidentally I don't agree that tram-trains should not be included in the 'longest tram route' discussion.
There has always been a problem worldwide with the definition/parameters of tramways versus light railways versus interurbans etc. How light is light, how heavy is heavy etc. Many urban systems (including Glasgow) have/had extensive reserved track with railway like features. Many sections of the already discussed Kusttram are also on reserved formation.
The received wisdom on this has changed over the years, and the technological coming together of light railway and tramway technology and vehicles in the last 25 years or so has further changed things.
The result in the 21st century (that I think most experts in the field would agree with) is that any route operated with a tram-like vehicle which includes a section of city street track, or city centre reserved track would be included in a list of 'tram' routes. Croydon and Manchester have sections of former heavy rail alignment but they are most definitely trams.
Bern route 6 to Worb Dorf now encompasses street tramway and what was the VBW - an 'interurban light railway' (but which used to run part way into the city on tram tracks even with the original 'heavier' light railway stock).
Incidentally Basel tram route 14 to Pratteln was also originally built as a 'railway' but has long since been considered a tramway - a typical example of the conundrum...
Shown as railway on the S and W atlas, and was built as such though IIRC it ran into the city centre overy tram lines from the beginning .
No, the Birsigtalbahn (BTB) terminated at a station at Heuwaage. It was linked up to the tram network in 1986 as part of the program to 'tramify' the BTB, at which time the light railway type vehicles were sold to the AOMC at Aigle
.