Since I decided to participate in the IndyLUG section of the massive inter-LUG train layout for the NMRA show in Detroit this July, I've found that it's been an interesting challenge in some ways. I'm going to focus on one of those challenges in this blog post - track bed building. We had decided that we were going to try to make track beds & use black tiles to make for more realistic-looking track instead of just laying down the basic Lego train tracks on top of the baseplates like we'd done before. There are several different ways of doing such track beds with Lego pieces - and credit should be given to Jeremy, who provided the basic design I worked from in making my version - thanks Jeremy! After looking at some actual track behind the Union Station building while taking pictures of the new Colts Stadium, I decided I'd go with using all 4 gray colors. Here's 2 pictures of what I came up with:

Large plates are under the track section, which allow for 1x2 plates to go between the track ties. Then black tiles are placed to suggest tarred wood ties. 1 x 1 round plates are put between the tiles to help break up the dark gray track ties visible. Then various 1x & 2x plates and 1x1 round plates are put along both sides to suggest the gravel track bed. Tiles and plates are put underneath the track section to support and hold it in place. I used green and gray baseplates for this because this is only 1 part of a very long straight section of 2 tracks side by side - the gray will be between the 2 tracks. Any baseplate can be used, depending on your needs for the layout. Also, the method allows for easy removal of the track if needed, such as using the track by itself without the sides or relatively quick conversion back to regular track. Here's a couple views showing how multiple sections look together:
Now, the next area using tracks necessitated a slightly different design. The 2 long tracks were to curve around my train station, and that meant they couldn't go neatly between 2 rows of track bed. I added ballast to the tracks themselves and made a track bed for the track to sit on, as seen here:
Note that I placed 1x1 round plates in the gaps along the inside edge of the curve track to help disguise the glaring gaps somewhat. Once I built all the track sections needed for the curved section, I laid them out onto the baseplates and first placed jumper plates at various points along each track. This helped to outline where the tracks would go and to hold the track sections in place. Then tiles were placed under each track edge to help support the track and provide the suggestion of gravel along the edges where plates couldn't be placed. Finally, various 1x1 and 1x2 plates were placed along the edges and topped with the 1x1 round plates. Here's a couple views of the track bed without the track on it:
As you can see in the 2nd picture, the track bed is split up into sections to allow for easy assembly/disassembling for the layout. The final picture gives a view of what the curves look like with the track on it:

The curve is made up of alternate straight/curve sections, as using just the curves would produce a radius too sharp for 8-wide trains to use safely. However, I've noted from rolling that car in the picture that they may still be prone to potential tipping if they go a little fast on that curve - probably because of the wheelsets shifting direction slightly in relation to each other while traversing a curve, straight, curve, etc.
Anyway, that's my solution to the building of realistic-looking tracks using Lego pieces. Please let me know what you think - suggestions for improvement are welcome! Soon to come - a post on another challenge - building brick roads!