Or mark them with some yellow/white lines or posts or something.
I think I could put level crossing posts to mark where vehicles can cross railway lines in the railway yards. This way they be easier to see where they are.
I never really thought what type of ground those original IRS ground tiles represent precisely
The reason some places used the blue metal dust (crushed ballast) was because it packs down better then normal gravel so when it rains it doesn't get washed away and have pot holes and water channels forming.
This pic is one of the Stations I worked at Euabalong West. Took this from top of the wheat silos. Passenger Train is the Silver City Comet traveling from Broken Hill To Orange. The freight train in the crossing loop is heading west to either Adelaide or Perth. The wheat train in the Goods siding on right is loading wheat directly from road trucks as it is harvest time. The wheat will be going to a flour mill in Sydney.
The grain loading rumps are gravel but that was not controlled by the railways .. it belonged to the Wheat Board. The Wool Dump and loading ramp up has the crushed metal dust on it and so does the road going under the gantry crane.
The railway tracks that can see on far left used to go to a loco siding where there was a turntable when station was first opened in 1919. I was there for 7 years in the 1980s the foundation work to the turntable was still there, but turntable had been removed. The siding when I was there had 2 other sidings attached to it .. one was a perway siding were it stored track maintenance machines and the other had 6 water columns for filling water wagons to supply isolated stations between here and Menindee. The water columns are connected to a water tower which is just off to the left of that siding.