More Shuttle Muttering
Here are some other multi-use paths that have shuttle/rental services
Lehigh Gorge Trail - Blue Mountain Sports
Virginia Creeper Trail - Virginia Creeper Trail Bike Shop
Bizz Johnson Trail - Lassen Rural Transit
Great Allegheny Passage - ATA trail shuttle page
Frenchtown or New Hope and Lambertville would be a prime location for such a shuttle/rental service, many car-free New Yorker's travel by bus to those locales on weekends.
Point Pleasant Canoe and Tube comes to mind since they already have shuttle vans for their river customers.