Job-creating corridors, construction hot spots, green spaces — there are big changes coming to Hall County in the next two decades. On Thursday, county government released a close-to-final draft of its updated comprehensive plan, the guiding document for planning and zoning that lays out how planners expect the county to grow in the next 20 years. The latest update relies on some new concepts, including corridors along major roads through the county — Interstate 985, Ga. 53 and similarly critical roads.