You're in luck! DART is one of the agencies that's taken the lead in
making its raw schedule data available to the public for developers
like you to use; the DART feed is available here:
http://www.dart.org/transitdata/
The data is in GTFS format, which is specified here:
http://code.google.com/transit/spec/transit_feed_specification.html
If you're a Python or Java developer, there are some libraries for
working with this data format in the GoogleTransitDataFeed open-source
project:
http://code.google.com/p/googletransitdatafeed/
As an aside, I'm happy to report that Sacramento RT and Orange County
Transportation Authority recently joined the set of agencies that are
making their feeds available for developer use:
http://code.google.com/p/googletransitdatafeed/wiki/PublicFeeds
Hope this helps,
Joe