I was reminded of this the other day. Had travelled out to West Lothian by train, taking the folder with me. Almost took a full sized bike, but thought I'd better bring the folder just in case space was an issue.
I was glad I did, as on arrival at the station coming back, learned that the next three trains were cancelled due to overhead line problems. What to do? Mid-evening, tired, not looking forward to cycling all the way back into Edinburgh, though just about doable I would be home in maybe two hours rather than 40 minutes.
So I doubled back and flagged a (First) bus, took the bike on folded, no problem. Stowed in the wheelchair space. Bus into centre, cycled from George Street instead of Waverley. Result!