I have written a one-location short film set entirely at a train station late at night. It doesn't seem too problematic to shoot, just show up and shoot late at night when the station should be empty or mostly empty. Of course we will be staying safe and not shooting on the tracks, the film does not call for that, it's just a conversation between two characters waiting for a train. My question is if I need to get permission in order to do so, and from whom, and if I need to worry about other logistics when shooting. This is really a no-budget production and we really won't be able to afford to pay for use of a location, hence my confusion about how to proceed. If there is an absolute necessity for it, the script can be easily adapted to another location, but the fact that it takes place at a train station is thematically important and affects the outcome of the story (as well as aesthetically pleasing to the director, who is me.) Do I need to worry about getting permission?