The Chicago Transit Authority elevated Lake Street Line (now the Green Line) goes straight west from the loop ... still does... pretty much unchanged... except for newer political posters and a newer generation of cars.
I rarely ever saw such a short train on any public transport system that doesn't use single articulated cars etc. on a normal basis. Makes me think of the times when trains still serviced all kinds of rural areas around here, and sometimes only had two cars behind an engine... Sights like these always fascinate me
These trains were always at least two units permanently coupled. There was only one cab in each car so two units back-to-back gave you bidirectional capability. The CTA tried articulation once [link] but gave up on it. I'm not sure why.
I kinda suspected that, the subway in Budapest also has at least two coupled units with one cab in each, though one line utilizes five car trains, so there you have one car with its rear coupled to another one's cab. But the articulated unit looks very peculiar somehow, really interesting
That system of being able to cross over between cab units has never been widely used around here, neither in trams, nor in real trains, like your shot [link] also shows. Those units were quickly converted into normal cabs, as engineers really hated being cramped into that small compartment.