Layout 

Where do we talk about layout?  I was curious about curve terminology, i.e. the fact that a two degree curve is sharper than a one degree curve, and where the degrees are actually measured, and what the relationship is to radius.  I found the answer easily enough with a google search, but it clearly ought to be discussed in Wikipedia somewhere, along with other details of railway surveying.  

It's somewhat amusing that we've got a whole article on Track transition curve, but no coverage of normal curves at all!  (That I can find.)

Does a "Layout" or "Surveying" section in this article make sense?  (I might just get bold and start adding it.) —