Photo is from Space Tower.
Step 2: Flat Spiral
Used in both Derezzed and Space Tower.
Step 3: Dual Track Connector Path
Step 4: Micro Roller Coaster Path
Step 5: Roller Coaster Bridge
Step 6: Alternate Elliptica Rails
IAC's instructable is here.
The rails are a little closer together, so the axle needs to be adjusted as well.
The top half attaches to the blue connectors at either end.