Varavon's latest product is a lightweight portable Tripod Track Dolly system. Most systems work with 1/2" to 1" tracks while the Varavon uses thin solid rails.
The Portable Track breaks down into individual pieces measuring 1m, and can be assembled to achieve over 16ft of run. Longer runs can be setup by purchasing additional track. The hard news is that this new track dolly system starts at over $680 dollars (found here).
Varavon Portable Tripod Track Dolly System