This support trestle platform is great to use to support track when you need to have another track underneath.  You can even fit 90 degree crossings on or under the platform.  This has been tested with Lionel Fastrack to work so it should work with other brands, just check the dimensions before purchasing.

These are 8 pieces, gluing recommended, and have an angled hole at the bottom to screw into your table to keep them from moving.  The top is a flat surface so it can be used with any brand track or to hold up scenery pieces as well.  It is approximately 6 7/8 inches tall, 4 inches between each support, and the supports are 1 inch deep.  There is approximately 6 inches of clearance underneath the cross beam.

Packages typically take 2-3 days to ship.

Track and train not included.