"A blue bus is going along the street."
Translation:По улице едет синий автобус.
Could идёт have been used here, because we're talking about the bus, not the passengers?
П.С. I was just taught (again) that public transport like buses идёт, while private transport and passengers едет. See also the notes on the Verbs of Motion skill: https://www.duolingo.com/skill/ru/Verbs-of-Motion/tips-and-notes
Could a native speaker comment?
Yes, but without context this would rather mean "The blue bus is going along the street".
Автобус does not have a Ь in the end.