They should just request a site near a bus stop...I am not a Ft Wilderness expert...try posting this on the camping board and I am sure someone can give you exact numbers of loops, but there are several bus stops and if they got a site near the end of a loop across from a bus stop it would be really close. Make sure they note on the reservation that it is for medical reasons. However, the walking he will need to do to get to the bus stop is NOTHING compared to walking around the parks...You might want to plan on a wheelchair. Also they might want to rent a golf cart if they will be spending much time at Ft Wilderness since it is a fair hike between the bus and dock, services, etc.