Indiana | Illinois | Michigan|
What do you do when an area code 'fills up'? When all the exchange codes (the second set of three digits) within an area code (the first set of three digits) are all used and the supply is exhausted?
The primary options are to SPLIT the area into two or more areas, each with it's own code, or to OVERLAY a second number on top of the first.
In 2001 317 was expected to need relief again by the 3rd Quarter of 2002 (that has now been extended until 2017) Indiana's 765 was expected to need relief by the 3rd Quarter of 2004 (that has now been extended until 2030). 812 was expected to need its first relief ever by the 4th Quarter of 2004. 812 is now nearing exhaust and will be overlaid in 2015.
Here is how I believe each of the three area codes should be relieved:
317 is easy. When the new 317 area was designed back in 1997 they started with an area where every call was local to downtown Indianapolis. The most obvious answer for 317's exhaust is an overlay. Performing a split of such a small area just isn't logical. The only "logical" split line would be a donut arrangement where 317 would become JUST the Indianapolis rate center. However many wireless numbers are centered on Indianapolis, and that rate center itself would require further relief in record time.
I look for an overlay (463 poss.) on 317.
The industry has recommended an overlay for 317, with 10D dialing to all local numbers, 11D required for long distance, and 11D permitted to any NANPA number. 7D will no longer be permitted within 317.
The current 765 is another large area similar to 219. I would split 765. I originally looked at a three way split in order to give the longest life, but conservation and number pooling may make a two way split effective. 765 is mostly rural.
The industry no longer recommends splits and the IURC overlaid 812. We may have seen our last area code split.
I look for an overlay (634 poss.) for 765.