You would need to add rules to your ARS table to keep that from happening. If the entire area code is local, it is pretty easy, just deny 1+area code dialing, or send it to a route patter that strips off the 1 for 10 digit dialing. I force all the users on my system to dial 1+10 digits for everything, and then I send it to the appropriate route pattern and the least cost route. It seems to work very good in my environment...
gblucas