markpierce .... Also, haven't you noticed the practice of "carving" rocks on concrete retaining walls along highways to resemble rock cliffs?
Ah! I can answer that one! It isn't to make the walls look pretty - at least not on roads it isn't - it's to break up the road noise. When the engine and tyre noise hits a flat surface it will bounce or richochet off retaining a lot of its volume. So by putting a lot of angles into the concrete face they break up / disrupt the bounce back - which also gets forced to cross other bits of itself so that the noise gets reduced even further.
Another way the RR copy us is to put in various underlay materials. Anyone modelling a modern track re-lay job might like to add in the truck loads of rolls of terrain matting getting delivered to site... or stacked ready... or sometimes bits of it stick out the side of the new ballast when it has been put in.
There are different fabrics for all sorts of situations. The main ones I've seen have been white, black or brown. The white is more like a fibreglass sheet in appearance - but isn't fibreglass. The black and brown are like heavy weave hessian sacking.
One of the products is called "Terram" (splg?) if anyone wants to do a search for it.
...haven't a clue when they started to use it...
A common, long-time model railroad scenery technique is to use diluted white glue (like Elmer's) to hold down soil and ground cover.
As evidenced at the following website, the "real world" has now following that practice. Here it is recommended as a method for dust control. I didn't notice a formula for diluting the glue before application, however.
http://www.midwestind.com/soilsement.htm
The local shortline railroad delivers the glue by the railroad tanker to the company.
.... Also, haven't you noticed the practice of "carving" rocks on concrete retaining walls along highways to resemble rock cliffs?
Mark