Cold, damp, barely lit up, and full of god knows what that would want to kill someone this is how everyone who got sent down there could explain the entire OSDRT tunnels and bunkers if you want to keep your stuff secret the best way to do it was do it underground and expand it like an ant column anyone who gets too curious disappears and become a guinea pig for either wing of the OSDRT. The main transportation to and from other stations was either walking or using makeshift trolleys ranging from manual push ones to fully armored and powered by small gasoline or diesel engine.
Of course, there will be some bad stuff that will come up and cause some serious damage that will result in a station being completely blocked off and abandoned such as station W-871 where a rabies outbreak resulted in it being blocked and the infected dying off from the disease and any survivors being left behind or maybe the infamous Dead-Man-Zone where extensive weapons testing and experimenting with the dead resulted in a large amount of land being contaminated of god knows what. The Dead-Man-Zone was like the ocean only a small part of the place was discovered and the rest have yet to be discovered same with the creatures however the DMZ brought out new things such as anomalies and the paranormal becoming normal to see in certain areas. With the DMZ appearing at first the OSDRT tried to prevent people from entering however when they realized that they don't have enough personnel because most of them are either defending the station or were part of the research team and most can't be spared for missions in the DMZ they started allowing people to go in and paying anyone to go and retrieve some stuff and get paid for it and so that's how the DMZ started flourishing with scavengers and hunters.
A small-sized tram manned by a crew of 3 and armed with 2 DHSK machine guns placed on the back and front of the vehicle with the 2 soldiers manning them even though the tunnels were a bit claustrophobic many will think that such large weaponry will be unnecessary however down here these tunnels had an infestation problem ranging from trespassers to mutated creature such as giant rats and moles you know things that would require a bit more firepower to kill them. On this tram were the new scavengers people who have yet to see the horrors.
As Tram got closer, the driver could see the entrance gate. He pulled the brake, allowing the tram to come to a stop in front of them. gate getting out of his seat, he got off the tram and walks towards and knocked on a door. Waiting a few seconds a slit opened up and behind it was a gas mask-wearing guard looking at the driver asked him a question "What have you brought now?" the driver looked through the slit gave the guard his answer "Well I brought more freshly grown green grass waiting to see the zone now let's hurry up my ass is freezing and I got other stuff to do" the guard gave a muffled laugh through his mask although while they couldn't see that grin the driver could tell by his eyes "Alright give me a second to open this door" closing the slit opened the door the metal screeching of noise indicates that it needs some oiling to it.
"Now hurry up and get inside," the guard said waving at the others to get off the tram and so the scavengers quickly got off and headed inside once they were in the guard closed the door and looked at the new guys "welcome to the farmers market aka E-49 take the time to look around it might be your last time visiting this place also before you go out to make sure to hit the 5 round clip bar and have one last drink hehe," the guard said laughing while walking back to his post.