The Great American Rail Trail is a huge promotional gimmick by Rails-to-Trails. Obviously, I'm not a big fan of RTC.
I'm of the opinion that RTC is another Washington-based heavy that sucks the oxygen out of the room.
The real trail work has always been at the local level.
In many places it is nothing more than a line on the map.
Much of the Cowboy Trail in Nebraska is nearly unridable deep sand.
Same goes for the eastern half of the Palouse to Cascades. (Doable, but rough)
So, I'd take that 53% with a box of salt.