Depends on how good the public transport is, BWL. Five miles can be quite daunting to a mom with a couple of kids and no wheels, or a teen with no wheels. Also depends on the roads, safety, etc. if the kid has a bicycle.
I personally don't think there are ever enough libraries and sometimes rural areas need them more than a metropolitan area as it IS more difficult to get from point A to point B in the boonies, no matter the population.
My maternal grandfather had the first lending library in New Castle, CO. I still have some of his books which have his name and the library number stamped in them. The current library there was built on land my paternal great-grandmother deeded to the city in exchange for social services in her last years. New Castle is not that far from Silt, Glenwood Springs, or Rifle, but it would be ridiculous for it not to have its own library, plus the commuting traffic and narrow roads would make it very hazardous and time-consuming for anyone to get to the other towns on foot or bike.