The assignment of area codes may seem random or even malevolent to you, John, but this merely reflects your troubled inner being. Actually it's pretty sensible. The North American Numbering Plan, of which the area codes are a part, was worked out in the late 1940s to ensure standardized numbering nationwide, helping to make direct-dial long distance possible. (Prior to that time you had to go through an operator.)
On the rotary-dial phones then in use, dialing a nine took a lot longer than dialing a one, which tied up expensive switching equipment. So AT&T assigned "low dial pull" numbers to the markets with the most telephones and thus presumably the highest number of incoming long-distance calls. New York got 212, Chicago 312, LA 213, Detroit 313, Dallas 214, and so on.
Some area codes aren't so easy to explain. Boston got 617 while comparatively rural western Massachusetts got 413; Washington, D.C., got 202. (Zero, remember, has the highest dial-pull of all.) Whether these anomalies represented some smoldering vendetta against the eastern seaboard we may never know; the people responsible have long since retired.
The issue of dial pulls became academic with the introduction of Touch-Tone phones in the early 1960s. Since then the guiding principle behind the assignment of new area codes has been to make the new number as different as possible from the adjacent old ones in order to avoid confusion. That's why the split of New York's 212 produced 718, LA's 213 begat 818, and Chicago's 312 was joined by 708. The drawback of this approach is that when you do make a mistake it's a lulu, giving you San Francisco, for example, when you were trying to dial Milwaukee. But the phone company will readily delete such goofs from your bill.
As far as Ma Bell was concerned, the real problem with assigning area codes was that it began running out of numbers to assign. Originally the switching system required that the middle digit in each code be a one or a zero, which meant there were only 152 numbers available. By the early 1990s, all but a handful of these had been spoken for. To get around this limitation, phone companies around the country began implementing "Dial-1" service, which required you to dial 1 at the start of any direct-dial long-distance call. This permitted the use of additional digits in the middle position, giving us a total of 792 potential codes. Just in time, what with the proliferation of area codes required by the growing use of cell phones, faxes, and modems. Phone company geniuses used to think 792 codes would hold us forevermore; now, who knows?
The assignment of area codes may seem random or even malevolent to you, John, but this merely reflects your troubled inner being. Actually it's pretty sensible. The North American Numbering Plan, of which the area codes are a part, was worked out in the late 1940s to ensure standardized numbering nationwide, helping to make direct-dial long distance possible. (Prior to that time you had to go through an operator.)
ReplyDeleteOn the rotary-dial phones then in use, dialing a nine took a lot longer than dialing a one, which tied up expensive switching equipment. So AT&T assigned "low dial pull" numbers to the markets with the most telephones and thus presumably the highest number of incoming long-distance calls. New York got 212, Chicago 312, LA 213, Detroit 313, Dallas 214, and so on.
Some area codes aren't so easy to explain. Boston got 617 while comparatively rural western Massachusetts got 413; Washington, D.C., got 202. (Zero, remember, has the highest dial-pull of all.) Whether these anomalies represented some smoldering vendetta against the eastern seaboard we may never know; the people responsible have long since retired.
The issue of dial pulls became academic with the introduction of Touch-Tone phones in the early 1960s. Since then the guiding principle behind the assignment of new area codes has been to make the new number as different as possible from the adjacent old ones in order to avoid confusion. That's why the split of New York's 212 produced 718, LA's 213 begat 818, and Chicago's 312 was joined by 708. The drawback of this approach is that when you do make a mistake it's a lulu, giving you San Francisco, for example, when you were trying to dial Milwaukee. But the phone company will readily delete such goofs from your bill.
As far as Ma Bell was concerned, the real problem with assigning area codes was that it began running out of numbers to assign. Originally the switching system required that the middle digit in each code be a one or a zero, which meant there were only 152 numbers available. By the early 1990s, all but a handful of these had been spoken for. To get around this limitation, phone companies around the country began implementing "Dial-1" service, which required you to dial 1 at the start of any direct-dial long-distance call. This permitted the use of additional digits in the middle position, giving us a total of 792 potential codes. Just in time, what with the proliferation of area codes required by the growing use of cell phones, faxes, and modems. Phone company geniuses used to think 792 codes would hold us forevermore; now, who knows?