Didn't Germany already do this ages ago? At night, they would broadcast various train trips[0]. I even recall there was a bit of a scandal when they cut out part of the trip through a tunnel, because the screen would be all black for too long.

[0] Just from a single camera at the front of the train, no further editing. I haven't seen the Norwegian and Swedish Slow TV yet, but I get the impression they use multiple cameras. The German version was super simple, but very relaxing in its simplicity.