I just finished the script. I really dug the concept. I love how the character basically go in an out of an alternate reality as if it were nothing special. I also love who the realities are very similar, but have grave differences.
However, on the rewrite I think you should focus on giving your characters distinct personalities. Unlike something like 2001, where characters don't delve into any type of emotions, there is a lot of dialogue in this and it seems like your characters are just dumping info, sometimes repeatedly. You don't really have anyone falling in love, suddenly Tom and Maria are together.
And sometimes you have characters speak like they are simply giving information, and too much of it, rather than seeming like two human beings talking to each other.
EXT. POLICE OFFICE - NIGHT [ALT]
Tom stops the car outside the office.
Alright, train will be coming in
about half an hour. We don't know
how long it's gonna stop for. But
it should be enough time to get on
You have a great story and concept, but if you worked on the characters it could be a lot more intriguing to the audience. The dialogue could take some big cuts, and you could add some more "human" moments for the characters.
Great work though, you have the makings of a real trippy flick here!