I've pretty much decided on Route 6 for the majority of my solo ride towards New Hampshire. While doing research on which roads I'd like to take, I came across this snippet on Wikipedia:
Since it was pieced together from other routes, US 6 does not serve a major transcontinental corridor, as other highways like U.S. Route 40 do. George R. Stewart, author of U.S. 40: Cross Section of the United States of America, initially considered US 6, but realized that "Route 6 runs uncertainly from nowhere to nowhere, scarcely to be followed from one end to the other, except by some devoted eccentric." In the famous "beat" novel On the Road by Jack Kerouac, protagonist Sal Paradise actually considers hitchhiking on US 6 to Nevada, but is told by a driver that "there's no traffic passes through 6" and that he'd be better off going via Pittsburgh (the Pennsylvania Turnpike). (Emphasis mine.)
If that doesn't describe a great motorcycle road, I don't know what does. I've ridden portions of 6 in both Indiana and Pennsylvania, and I surely now fall into that category of "devoted eccentric."