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!

Tuesday, October 28, 2008

What is TransCAD and why are we here?

TransCAD is a fully integrated travel modeling and GIS software widely used by transportation planners around the world. It is a powerful tool which provides valuable information to decision makers about the transportation system.

It can also be a pain in the ass.

That is to be expected, though, when you combine a complicated proprietary software with extremely large and complex files and spread it across a variety of users ranging from programmers to planners and with vastly different levels of experience.

So why are we here?

For one, we are here to have fun and share stories, vent, and if we get bored, even talk about work (but lets hope not). Secondly, it's important that there is a place where users of vastly different levels of experience can share in a love/hate relationship with our friend, TransCAD. And third, a place to ask questions. When I say ask questions I mean REAL questions, any questions. Those who have been working with travel models and TransCAD for a long time have a tendency to forget what it was like when they were learning and how foreign this stuff can sound.

So feel free to blurt out anything you want at any time. It doesn't matter if you need help changing the colors on a line layer or if you can't figure out why your Vehicle Miles Travled tripled for no reason and you want some help trouble shooting.

We are all here to learn...and then bitch about how it doesn't work!

A bit about me. I have been using TransCAD for about five years. I wouldn't call those five years of advanced practice however as I've wasted more time than I'd like to admit trying to figure out things like transposing and adding matrices or figuring our what REALLY the difference is between Production-Attraction and Origin-Destination.

A couple other facts about me and TransCAD:

I've never built a model but I can appreciate an intuitive interface.

I often pace around the room when I'm waiting to see if a model will run successfully.

I once gave a presentation on the four step modeling process to a statewide group of TransCAD users and didn't include Trip Distribution as a step (It wasn't a joke either, I just didn't know what I was talking about)

I'm good at sounding like an idiot when I talk about TransCAD and modeling cause I only kinda get what I am talking about.

I've found it's as fun to complain about it as it is to learn something new about it, which is why I started this blog.