Boston-area residents will likely have to dial three extra digits just to call down the block starting in 1998.

Responding to an exponential growth in population and phone lines, NYNEX is planning to add two new area codes to Massachusetts, The Boston Globe reported. One potential plan calls for interspersing the new area codes into the current ones, rather than creating geographically-defined regions for the codes.

According to the phone company, the 617 area code will run out of new numbers in two years and the 508 region will be exhausted in three years.

The Massachusetts Department of Public Utilities must decide before the end of the year how to distribute the new codes. One option is an overlay plan, assigning new numbers to newly-installed lines within the old area codes. The other is the traditional "area code split," in which invisible lines are drawn within the area, resulting in changed numbers for the current residents.

NYNEX officials hope to implement what they call the "geographic overlay" plan. This would keep current telephone numbers in eastern Massachusetts the same, but would install new lines in the immediate Boston-area section of the 781 area code and other lines in outlying areas of the city part of the 978 region.

Proponents supports the overlay plan because of its convenience: No existing numbers would change.

Two new area codes will not provide an eternal solution to Boston's number crunch. With the increasing popularity of personal technology, more and more telephone numbers will be required to support new crops of pagers, computers and direct-dial extensions. According to NYNEX, with the overlay plan, new numbers can be implemented as needed.

However, the overlay plan is complicated by recent action by the Federal Communications Commission. Under its ruling, an area that adopts an overlay plan must also implement 10-digit dialing for all telephone calls. A caller in the 617 area, for instance, would not have to press 1 before dialing the new 781 area code.

Attorney General L. Scott Harshbarger '64 opposes the overlay plan on grounds of fairness.

"Every new homeowner and every new business that moves into certain areas is likely to be assigned completely new area codes," said Harshbarger. "That's overly complicated, confusing and unfair."

Harshbarger wants NYNEX to adopt the "geographic split" reminiscent of the last area code change in 1988. With the split, the current 617 area code would be split into 617 and 781. A portion removed from the 508 area code would have the number changed to 978. The result is 1 million people with changed area codes.

But NYNEX officials insisted that the overlay system is more convenient.

"Fundamentally, it's the plan that is the least disruptive to our customers," said Thomas DeSisto, NYNEX managing director of the regulatory planning.

DeSisto said the overlay system is a "long-term solution to the whole issue of telephone numbers and rapid growth that we see now and that we have seen over the past five to 10 years."

When dialing outside the campus, Harvard students will be affected by NYNEX's choice.

"Having a 10-digit phone number is too inconvenient," said Cinthia Guzman '00, who is supportive of the geographical split. "Harvard students will have a problem going from four digits to 10."

Alison Kent '99 agreed and said that she believes avoidance of new numbers on the grounds of inconvenience is wasted energy.

"As long as NYNEX ensured that there would be a recorded message with my new number, I don't see any major problem," she said.

Some students said they feel the conflict is exaggerated.

"I'm fairly impartial," said Young In '98. "It's only three extra numbers. It's not that big of an inconvenience."

NYNEX will not make a final decision until the end of the year