I completed a 48/10 in 2002. I was the 13th person to accomplish it. The route planning was a complex, time consuming endeavor in those days as there was not nearly the amount of previous knowledge about the event nor was there the technological advantages that are available today.
Over the years, I've only seen two basic routing schemes that are time and mileage efficient....the Ayres method and mine. My route is essentially an inland outline of the US boundaries. At the time, I completely developed my route without influence or input from any other previous 48/10 rider so I will boldly call it "mine"! Lol! The Ayres route was predicated on him going for a record attempt at a 49/10 that started in Kittery, ME and ended in Hyder, AK. Ayres solved many of his logistical problems with incredibly extensive planning and the use of dozens of helpers along the way. He was also one hell of a long distance rider!
Trust me, my ride was not anywhere near a record but it was done 100% solo with only a road atlas as my guide. My 48/10 route can be adjusted to start and end in a variety of locations around the United States with the final mileage total only varying by a couple of hundred miles.
I'm seriously considering another 48/10 attempt in 2016. I made lots of time consuming and strategic mistakes the first time and it's been bugging me ever since that I could do much better and probably shave many hours off of my previous time. Just for variation, I may make it into a 49/10 which is a different animal entirely.
The 48/10 was and always will be the pinnacle of my riding career. I've done several more difficult rides since then but the 48/10 was uniquely difficult and fun.
Go for it!