Monday, November 10, 2008

Editing Route Systems in TransCAD

Today I was editing both a road and transit network to reflect programmed projects in the Transportation Improvement Program. The road network edits were simple and straightforward, in fact, they didn't even involve any geography editing, just updating some attributes.

The transit route system updates were not nearly as enjoyable! I'm using TransCAD version 5.0 which I've found, in general, to be easier to work with route systems but I ran into some frustrating situations today. While adding an entirely new route and deleting an entire existing route went off without a hitch I ran into a shit ton of errors when I tried to extend a portion of a route from a stop in the middle of the route along a perpendicular road and back. I was finally able to get most of the route altered by realigning nearly half of it. The bitch of it was when I saved the edits, I hadn't deleted the stop on the second pass which, for some reason, changed the pass count field in the stop layer to zero and created the evil .err file.

Then I discover that the stop layer can't be opened with exclusive access so that the attributes can be changed. After 20 more minutes of staring at the screen I figured out that I could use the map editor to manually delete the points in the stop layer.

So, I think I was able to fix the stop problems but then I discovered that the additional part of the route that I'd inserted had this weird loop in it I couldn't get out no matter how I selected the route (shortest path or click segments) so that it.....shit I think I just figured it out! My road network includes local roads for display purposes and when I created the .net file I didn't select out the locals. Fuck! That would have made everything a heck of a lot easier. No wonder I was having so much trouble getting the routes to display where I wanted them.

Eureka! Of course I have tomorrow off work in observance of Veteran's Day, and by the time Wednesday comes around I'll probably have forgotten the problem!