This is a good question Michelle. There have been a number of discussions about alternate modes of transport within the Great Smoky Mountains National Park. Two that I am most familiar with are in the Cades Cove area and the discussion of Greenway connections to the park from surrounding areas.
Here is a little more info:
A regional greenways group is looking into the Greenway connections: http://www.smokymountainsgreenways.org/.
More information on the Cades Cove Project can be found here: http://www.nps.gov/grsm/parkmgmt/upload/Brief-Cades%20Cove%20Planning.pdf
We'd love if you can expand on this idea further!