I came across this on the old forums and wondred why nobody had the sense before to make sure this usefull info was posted where it could be found back easy. I take no credit for finding out how to do this, the original idea seems to come from a player named Alanch who seems to be no longer on steam.
Have you ever had the game crashing on you and got told to clear cache only to find that the game crashes before you reach the Tools section in Train Simulator. Here is how you can clear cache easy without going into TS, you don't even need to have steam running to do it.

open a notepad and type the following code

save this using the "all files" option with the name ClearBlueprints.bat you have done it correctly if the file icon is a square with two gears in it.

place this in .../Steam/steamapps/common/RailWorks/Assets
douleclick to use

a CMD window should pop up showing you the deletion of the files followed by "press any key to continue" and pressing the any key (usualy located near the fluxlight on the back of your keyboard, if you can't find or have it just use Esc) should close the window, you have cleared cache

Additional Option
add if you do a lot of editor work, it will remove the bak files that are generated after you made a new scenario/route edit save

do not use outside the Assets Folder

Mavadelo