When our 2nd area code was added, the city was split with 713 for addresses inside the beltway and 281 for those outside. There was a lot of expense for those businesses with new numbers - having to print up new letterhead, notify customers, etc.

When the 3rd area code was added they went with the overlay plan due to all of the complaints about the costs from before.

Pennsylvania gave up on splitting areas because numbers where being added so fast they couldn't keep up. That seems to have peaked though, the real problem was back in the 80's when home users started using multiple numbers. Between cell phones, modems and faxes, even home users might have 3 or 4 numbers.

Jay