Ground cover for an industrial area: A few questions

I would just blend something yourself and lay it down manually. Those mats look convenient but you end up with seams to hide and cost a fortune compared to just laying it down yourself.  When I need to make junk, I get a gladware tub and dump in quite a bit of dirt colored ground foam, a little bit of dark green, light green and yellow (for weeds), a bunch of HO or N scale sized ballast, a little O scale ballast and shake it up. Assess what color you have and adjust from there. 

When you go to lay it down, this is what I do... heavily coat the surface with white glue (undiluted). Use a cheap paint brush and lay it on thick. If you want to accent certain areas with stuff like more gravel or tan foam to simulate saw dust, keep that separate for now. 

Take your mixed up container of covering and lay it down. I usually just dump piles and spread it around by hand, it goes where you want it much easier than a shaker can. Dont worry if you have some heavy spots and light spots, just DONT dump it all out yet. 

Once you have it where you want it, give it a few minutes to soak in. Once the glue soaks through, take the colors/textures you held separately and put them where you want. This is also when you'd do static grass if you're inclined. Over the top of your accents, just pinch and sprinkle a little more of your mixture on top, to blend them in so it doesnt look like someone made a huge mess that day. 

If you want to put in weed tufts, this is a good time to do that too. 

You have a decent amount of time to work more foam in with this but once its down, dont touch it or you'll smear the glue and end up with a funny spot. 

After you're happy, go over it lightly with a spray bottle of diluted white glue. Not too much! You dont want it to dry hard as a rock. Just enough to stick down the surface.

Thanks. That's very helpful advice. I didn't think about seems, but they will be there. The pic you sent really helps visualize your technique. It's excellent. I greatly appreciate your help.

I agree with Boilermaker - If the track was not down then mats would be ok. At your stage it is better to use the Woodland Scenics or Scenic Express products.

Products like that are handy on steep slopes, but I agree with the others that DIY is better in your situation. You want a lot of variability from area to area. A too-uniform base is something that you would just fight against. IMO you also don't want a perfectly flat surface. Use the opportunity to add a little vertical relief. In doing this, you can hide the toy-like bases of some of those accessories:

Pete, thanks for the good advice and the pics. I've thought about relief, but those pics help me better visualize it. I like the area aound your 97 Coal Elevator.

Fairly simple solution i used was to get an 80Lb. bag of sand from a local distributor (He carried sandbox sand, beach sand, and about 4 other varieties) that was the size and color (more grey than tan) i wanted. Some big box stores carry sand as well but not many varieties. This was less than $5. Put it down using the basic white glue/water/dish detergent method. Then took a cheap (WallyMart) rattle can of flat black and dusted various areas where i wanted to simulate oily dirt. Done!

Jackson, good idea, thanks.