The OTOL Louisiana-Texas RailFest 2018 promises a lot of train riding in a few cities. However there seem to always be some exceptions to the rule as to what's available for us to ride. To name a few:
We plan to ride all three of the existing light rail lines in Houston that have been fully completed: the Red, Purple, and Green Lines. However when the Metro light rail system was conceived, there were supposed to be five lines. The other two have not had funding sources identified. The University Line (or Blue Line) would cross the existing Red Line at the Wheeler station and run on an east-west axis. It is also supposed to interface (and interline for a short distance) with the existing Purple Line. The other line, the Uptown Line (or Gold Line), would be dependent on the Blue Line to connect with the rest of the system, as it would intersect with it at the Bellaire station. It would serve the edge city area around the Galleria Mall and other nearby shopping destinations. The Gold Line is currently under construction as a Bus Rapid Transit line, with contingencies to convert it later to light rail.
Traffic on I-35 between San Antonio and Austin is so bad that a commuter rail line, dubbed Lone Star Rail or L-STAR was envisioned to not only connect these two cities, but also run up as far north as Georgetown. There was even talk of Union Pacific Railroad (UP) rerouting its freight trains off the direct rail line that parallels the freeway to allow frequent, 90-mph service on corridor. However, UP backed out of the deal in 2016, thus killing the entire project. There have been studies to see how Amtrak could become a partner in an alternate venture without UP's cooperation.
The MetroRail commuter service between Austin and Leander is NOT a part of what this service would have been; more likely L-STAR would have followed the corridor used by Amtrak and served the latter's station in downtown Austin.
Some years ago in planning Fests for the future, L-STAR was penciled in as the way to go between the two cities. Unfortunately all that still exists is the once-daily Texas Eagle, which does not work well for one to commute between the two cities at convenient times.