FWIW, two Railtrails we have ridden have very rough surfaces with stones protruding from the fine gravel surface (unless resurfaced since). The Hiawatha Trail and the Virginia Creeper both see heavy use, both have not-insignificant user fees and both desperately need resurfaced. The Creeper is so worn down tree roots are exposed in places! This was 2012 for the Hiawatha and 2014 for the Creeper. Both are wonderful rides and both offer shuttle service to the top. The Mickelson Trail Southbound out of deadwood offers shuttle service to the top as well. IMO the most scenic portion of the Mickelson is either direction out of Mystic trailhead.
