OK, So What Was With the Weirdly Surreal Trains Theme in the 90's?

I've always loved the surreal, vaguely-futuristic feeling the Trains line had in this era. Why are they all in huge blue caverns or cliffsides? Why are the tunnels glowing like there's magma close by? Why is the sky glowing like an alien planet? Why is there snow in the yard? We'll never know for sure, but whoever designed these dioramas was on a different planet (possibly literally). I know it's overused, but it was probably child-me's first exposure to liminal reality and really allowed my...