As to Corridor G, the area it passed through just south of Charleston, now called "Southridge" by developers, or just "Corridor G" as in "I'm going to shop out Corridor G", was pretty much unpopulated before the highway was built. What few lived out there were mostly backwoods types, combined with some old hippies who wanted to grow their dope in peace.
When the road was finished, there was some housing development, but the main deal was retail. Back in the 80s Charleston foolishly built a downtown mall, rather than the typical suburban mall that most metros of that size got, which was always inadequate and avoided by many (for example, most Putnam Countians who work and everything else in Charleston, shop at the Huntington Mall, a traditional suburban mall) back when malls were important.
Thus the land was quickly developed into four large strip malls. The side effect of this, sadly, has been to cut the effectiveness of Corridor G itself for inter-regional transportation. The last 10 miles of US 119 will take you at least 20 minutes at best, sometime far more, to connect to the interstate. Remembering that the purpose of the system was to help people in rural Appalachia, not to provide access to a new mall, this is unfortunate.