Busses with passenger trailers I haven't seen, but 'harmonica' busses have been around since forever
They run double-jointed ones over here too. Apparently busses are more flexible than lightrail and do the same job. Who knew.
..and then I googled, and it turns out 1 of the local bus companies imported a swiss bus-trailer to extend the capacity of busses during rush hour. Too bad transporting people in a trailer is banned in the country, so after a few test drives in 2015, nothing further happened with it.
Youtube clip:
https://youtu.be/MAYYf9CRrTg
And of course, holiday busses with trailers to take bicycles in summer and ski gear in winter.
