How long are the available pool of area codes expected to last?
What are the projected long term solutions? Four-digit area codes or four-digit exchanges?
How long is the pool of available. . . .
What are the proposed. . . .
You might also want to look at LincMad’s site:
He suggests twelve-digit phone numbers: four-digit area code and four-digit exchange code.
There is also good info, and a “code clock” at Areacode Info.
And the source of that quote was http://www.lincmad.com/future.html.