I could really talk you out of wanting a DEM ... but if you really want a DEM ? What is the route or area that you are requesting ? ... and someone that does have experience in making a DEM can help you.
My present DEM is well over 10,000 baseboards, and laying gradients and curves are a real chore ... over the flat baseboard method !
I feel your pain!!! The red and blue lines are great
as a guide, and TransDEM will also drop in the track too, if you let it, but the TIGER data and the DEM data aren't dead-on accurate with each other, and you get some REALLY wild roller coasters that need fixed. My Mon Valley DEM is tough enough as it is, and it pretty much follows a river. I've got the N&W line that goes "cross country", and even cleaning it up as best as I can, I've got some 8% grades that I
know are not right and need some cut and fill to knock them down. You're talking
serious mountains on your part of the state, Cascade!
It is
hard work on a game in a computer, with "undo" only a click away. I feel for the guys in the 1800s and early 1900s who had to figure out how to blast, dig, cut, and fill their way through (and under!)
real mountains and over
real rivers, valleys, ravines, etc.!!
I'm not really sure what I have right now in terms of size, but the Ten Mile Creek branch to Emerald Mine added a lot more work (about 25 more miles), and I've got more of that line (Manor Branch?) that goes out to Bailey Mine that is not merged in to it yet. Part of what I was doing this week is pruning unneeded baseboards and cleaning up the map itself.
Something that I've found out (the hard way), is if you start with TOO big of a DEM (especially for me when the ADHD kicks in), you start working here, then decide, "I want to work there" and you go crazy all over the map.
TransDEM uses certain references (in my example, I am using a MASSIVE DEM of Western Pennsylvania) to keep everything aligned. I have already merged two routes into one with a third "module" waiting in the wings to be merged in. If and when I finish what I have so far, maybe I'll work my way up to Pittsburgh. I'd like to work my way out the N&W line too, to wherever that takes me.
(See how the ADHD takes me off on a tangent?) Anyhow, point is, Cascade is right. DEMs make
beautiful prototypical routes, but they also make monsters that you may never finish.