The structure I am looking at is the arch supporting the weight all the way to the ground. This is the easiest way to allow access to the roof by bike or foot. The center oval area would be a giant opaque skylight allowing the entire track to be day lit without creating hot spots or shadows on either the track or spectator seating area. The idea of this is to do a green roof over the structure so it would look like a giant grassy hill.
Structure #1
Very symmetrical building with 4 main small cutouts/entrances. I was thinking of using each one as a gate to that particular sport (track, cyclocross, mountain, crit) so that entrance could act as a meeting/waiting point for people entering/leaving the facility.
Structure #2
Same as above but with larger openings and more N/S/E/W opening configuration. This allows for more exterior glass which would help it to be recognized as a building and not a giant hill from I-35 and the boathouse district across the river.
Structure #3
This option has larger cutouts at the main entrance (left side) and smaller ones around the rest of the building. In this option I plan to stop the exterior wall at the column row this allowing the rest of the space to be covered exterior with the smaller circles acting as protected sitting/meeting areas so you can watch the action at the river as well as people riding around the site and on top of the building. This option is an evolution of the above structure system as well as my favorite of the 3. It still allows access to the roof (mainly on the back side) as well as creating stunning views under the green roof at the building itself. Moving the exterior wall inside the green roof allows me to use more glass and create better views around the area.