Rails to Trails is a wonderful idea and active organisation. It promotes the banking of the nation's RR rights-of-way in case of any unforeseen future need for rights-of-way, and helps convert them to outdoor activity trails.
I encountered these back in my younger days when i was Mountain Biking.
We have several here in SE Michigan and they are in use all over the United States.
One is even being developed by architects on an unused New York City elevated railway. It's on the West Side and it's called "The High Line".
Except I can't think of a single instance where they didn't fight tooth and nail against converting those ROW back to any of the needs they claim they are preserving the trail for, such as transit. That line seems to be just a ruse to get support and funding for recreation trails.