I've been working on the tracks around the facility lately, mainly weathering them.
I used some black and brown Bragdon powders to make the tracks look dirty and oily. In a few spots I wanted to make it look wet from fuel spills. I achieved this by using a small dollop of glossy Mod Podge and thinned it to a wash and then applied it to the areas where spills would likely be. It soaked in and when dried it looked wet. I also did this around some of the piping and hoses.
The other thing I added were some wheel stops. These were purchased off of Etsy from a guy who makes some N scale 3D printed items. These are pretty nice little wheel stops.