I am looking for an art-type movie, that starts with very heavy meteorite bombardment of Earth. A colony of engineers end up living underground, in a highly mechanized society. Brain-damaged "bandits" try to eat them down there. Eventually a young lady helps a couple of engineers escape to the surface, years after the meteorite strikes have ended. They end up in a deserted railroad yard, where the trains standing there are in the colors of the old South African Railways (red and white carriages). Eventually the lady helps the escaped engineers deal with emotional trauma, after they rescue her from a perverted cannibalistic colony.
Is it Broken Darkness?
It's a South African film from 2017. Humanity has been forced underground by a massive meteor shower. Our heroes (two men and a young woman) come under attack from mutants, bandits and cannibals. Eventually they make it back to the surface.
This trailer sounds like a mix of American and South African accents and shows the initial meteor bombardment. There's a shot of railway lines above ground, although it doesn't show any trains.
Is it possible you're thinking of The Last Train, a British six episode post-apocalyptic television drama, first broadcast on the ITV network in 1999?
A random group of individuals on a train to Sheffield are cryogenically frozen when a canister of gas is released in their carriage. They unfreeze to find the world in ruins. Decades have passed; they are some of the few humans to have survived an apocalyptic asteroid strike and are alone in the British countryside. It is revealed that one of the group, Harriet Ambrose (Nicola Walker), knew of the incoming asteroid strike and had been on her way to a top-secret government project known as Ark.
Harriet wishes to track down the Ark team to find her boyfriend, scientist Jonathan Geddes (Ralph Brown). The rest of the group agrees to join her, since it seems like their best chance to find other survivors and a safe haven. On the way they must deal with the dangers of the post-apocalyptic world, such as feral dog packs and tribes of seemingly hostile humans.
It doesn't match in that it's passengers, not engineers, and they're cryogenically preserved rather than living underground, but they are led by a young woman to the surface, and they are attacked by savage survivors. Also, it does not open with the meteorite strike, but with the patients boarding, followed by them getting frozen and then waking up.