I want to build a routing index (.rtg file) based on all roads in the USA. But when I do routing I'd like to just query the roads in the area I'm currently interested in...say a county in NJ. The purpose is to reduce the memory requirements (speed, etc.).
I'll be putting my road features in an SQL database and just query an extent that I am currently interested in, and then build a featurelayer based on the results of the query, i.e., a county in NJ. So my question is, can I do that and use a larger overall index (.rtg file)?